Molecular Phylogeny of Pectis (Tageteae, Asteraceae), a C4
Genus of the Neotropics, and its Sister Genus Porophyllum
Author(s): Debra R. Hansen,. Robert K. Jansen,. Rowan F. Sage,. José Luis
Villaseñor,. and Beryl B. Simpson
Source: Lundellia, 19(1):6-38.
Published By: The Plant Resources Center, University of Texas at Austin
URL: http://www.bioone.org/doi/full/10.25224/1097-993X-19.1.6
BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the
biological, ecological, and environmental sciences. BioOne provides a sustainable online
platform for over 170 journals and books published by nonprofit societies, associations,
museums, institutions, and presses.
Your use of this PDF, the BioOne Web site, and all posted and associated content
indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/
terms_of_use.
Usage of BioOne content is strictly limited to personal, educational, and non-commercial
use. Commercial inquiries or rights and permissions requests should be directed to the
individual publisher as copyright holder.
BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit
publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to
critical research.
6
LUNDELLIA
DECEMBER, 2016
MOLECULAR PHYLOGENY OF PECTIS (TAGETEAE, ASTERACEAE),
A C4 GENUS OF THE NEOTROPICS, AND ITS
SISTER GENUS POROPHYLLUM
Debra R. Hansen,1 Robert K. Jansen,1 Rowan F. Sage,2 José Luis Villaseñor,3
and Beryl B. Simpson1
Department of Integrative Biology, The University of Texas at Austin, 205 West 24th Street, Austin,
Texas 78712, USA, email: debrahansen@utexas.edu
2
Department of Ecology & Evolutionary Biology, University of Toronto, 25 Willcocks Street, Room 3055,
Toronto, Ontario, Canada M5S 3B2
3
Departamento de Botánica, Instituto de Biologı́a, Universidad Nacional Autónoma de México,
Apartado Postal 70-233, 04510 México, D.F. Mexico
1
Abstract: Pectis is a genus of 690 xeric adapted New World species. Previous molecular
phylogenetic studies showed Pectis closely related to Porophyllum, and one analysis
resolved Porophyllum species nested within Pectis. Some Pectis species are known to use
C4 photosynthesis. Here we investigate the phylogeny of Pectis and Porophyllum,
examine the ploidy levels and geographical distribution of Pectis species in light of its
phylogeny, and infer the origin and extent of C4 photosynthesis in both genera.
Chloroplast and ITS data from 78 Pectis and 22 Porophyllum species were used to test
the monophyly of Pectis and its previously described sections. Carbon isotope data were
obtained to infer the photosynthetic pathway of 80 species, and the results mapped on
the inferred phylogenies to determine the timing and pattern of evolution of the C4
pathway. The ITS dataset supports a monophyletic Pectis sister to a monophyletic
Porophyllum, while the chloroplast dataset places two Porophyllum species sister to
a combined Pectis+Porophyllum clade. Five well-supported lineages are recovered in
Pectis. All Pectis sampled have L13C values consistent with C4 photosynthesis, and all
Porophyllum species sampled have L13C values consistent with C3 photosynthesis. We
conclude that Pectis is monophyletic but only two of its recognized sections are
monophyletic. Porophyllum is monophyletic but its sections are not. Porophyllum
amplexicaule and Pr. scoparium should be treated as members of a new genus. The
switch to the C4 pathway in Pectis happened in the late Miocene, probably in north/
central Mexico, at or after the divergence of Pectis and Porophyllum. This location and
timing is consistent with the evolution of C4 photosynthesis in other North American
eudicot lineages, suggesting similar environmental conditions may underlie the switch
to C4 photosynthesis.
Keywords: Asteraceae, C4 photosynthesis, Pectis, Pectidinae, Porophyllum, Tageteae.
Pectis L. is the largest genus in the
marigold tribe (Pectidinae: Tageteae: Asteraceae), and comprises about 90 annual and
perennial species (Keil, 2006) adapted to
warm, arid regions of the New World.
Species are found in deserts, thorn scrub,
coastal plains, savannas, and openings in
seasonally dry tropical forests and oak-pine
woodlands. Pectis is most diverse in Mexico
and the Caribbean, but its species range
from Wyoming and Nebraska in the U.S. to
southern Brazil and northern Argentina.
Two species are endemic to the Galapagos,
one is introduced in Hawaii, and one has
LUNDELLIA 19:6–38. 2016
recently been naturalized in Taiwan (Jung
et al., 2011). Pectis is distinguished from the
other Tageteae by its combination of simple,
opposite leaves with pairs of bristles at their
bases; phyllaries that are each adnate to, and
subtend the base of, a ray floret (often falling
as a single unit at maturity) and very short
and often densely papillose style branches.
Most Pectis species have noticeable oil glands
on their phyllaries and on the margins or
undersides of their leaves, a character they
share with other genera in Tageteae subtribe
Pectidinae. The oil of Pectis species often has
a strong medicinal, spicy, or lemony scent,
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
and various Pectis species have traditional
culinary or medicinal uses (Asprey &
Thornton, 1953; Bye, 1996). A few species
have a distasteful odor likened to that of
stinkbugs, leading to the common name
“cinchweed.” Pectis angustifolia has a high
thimole content (Albers, 1942), and Pectis
papposa has been suggested as a potential
source of commercial food and beverage
flavoring because of its high cumaldehyde
and carvone content (Bradley & HaagenSmit, 1949). Phototoxic, antibacterial, and
antifungal properties of Pectis oil have been
reported (Downum et al., 1985; Downum &
Rodriquez, 1986; Downum et al., 1989; da
Silva et al., 2005; Soares et al., 2009). Pectis is
noteworthy because some species previously
surveyed were shown to use C4 photosynthesis, a photosynthetic pathway that confers
enhanced efficiency in conditions of high
heat and high light intensity (Sage et al.,
2011). C4 photosynthesis is uncommon in
eudicots, and especially rare in the Asteraceae, in which just 0.3% of the genera use
the C4 pathway (Kellogg, 1999).
The goals of the present study were to
clarify the relationship between Pectis and
Porophyllum, test the monophyly of previously described generic subdivisions, and
determine the age, origin, and extent of the
evolution of C4 photosynthesis in Pectis. We
primarily focused on the phylogeny of Pectis,
but sampled deeply in Porophyllum to
confirm the relationship between the two
genera. Using a greatly expanded sample of
78 Pectis and 22 Porophyllum species and
varieties, we provide the first molecular
evidence for relationships within the genera,
and suggest direction regarding sectional
organization for both Pectis and Porophyllum. We also present carbon isotope values
for 62 Pectis and 18 Porophyllum species and
varieties, the first comprehensive survey of
photosynthetic pathway for both genera.
TAXONOMY. Linnaeus included two
species of Caribbean Pectis (Pt. ciliaris L.
and Pt. linifolia L.) when describing the
genus in 1759. Pectis was included in the
original circumscription of tribe Tageteae
(Cassini, 1819) along with other former
Heliantheae genera with leaves and phyllaries bearing glands. Based on molecular and
morphological similarities, Panero (2007)
included Tageteae in his Heliantheae Alliance, placing the traditional Tageteae genera,
including Pectis and Porophyllum Guett.,
into subtribe Pectidinae.
The most extensive taxonomic treatments of Pectis are by Gray (1849, 1852,
1884, 1888), Fernald (1897), and Keil (1975,
1977a, 1978). Gray described six subgeneric
divisions within Pectis based largely on
differences in pappus elements (1849,
1852). By 1883 Gray recognized just three
sections, Pt. sect. Eupectis, Pt. sect. Pectothrix, and Pt. sect. Pectidium. In 1897
Fernald elevated the sections to subgenera,
and used pappus characters to assign 34
North American species to five subgenera:
Eupectis, Heteropectis, Pectothrix, Pectidopsis
(resurrected from Gray 1852) and Pectidium.
Fernald’s treatment remains the most complete revision to date.
In the mid-70s, Keil revised four of the
Pectis subgenera. For Pectis subg. Heteropectis (1975) and Pectidium (5 Pt. sect.
Pectis, Keil, 1978) he followed Fernald’s
treatment of the species (two species in each
section) but reduced the subgenera to
sections. Although various workers used
pappus characters to segregate Pectis into
different genera (Lessing, 1830; de Candolle,
1836) or divide it into sections or subgenera
(Gray, 1849, 1884; Fernald, 1897), these
characters can be variable, even within
populations. In 1977, Keil dismantled subgenera Pectothrix and Pectidopsis, using some
species from each (as well as a few previously-unassigned taxa) to form a redefined
Pt. sect. Pectothrix. Keil included species in
Pt. sect. Pectothrix based on a combination
of characters – position of foliar glands,
shape of capitula, number of ray and disc
florets, and corolla pubescence. In spite of
these significant revisions, fewer than half of
Pectis species have been assigned to sectional
rank, and no treatment has covered the full
geographic range of the genus.
7
8
LUNDELLIA
Porophyllum is a genus of about 25
species of annual herbs and perennial shrubs
(or subshrubs) found from the southwestern
United States to southern Brazil, including
the Caribbean islands. Some are aridadapted but, unlike Pectis, many species of
Porophyllum occur in mesic areas. Like
Pectis, they have prominent oil glands on
their leaves and phyllaries but in Porophyllum the scent is usually described as strong
and unpleasant. The genus differs from
others in the Tageteae by its combination
of well-developed leaves, discoid heads, and
a pappus entirely of bristles. In the most
recent treatment of the genus, Johnson
(1969) placed Porophyllum species into Pr.
sect. Hunteria Moc. & Sessé (DC.) and Pr.
sect. Porophyllum based primarily on leaf
characters and habitat. Species of Pr. sect.
Hunteria have thick leaves that are sessile to
short-petioled, with narrow blades and are
distributed in arid or semi-arid Mexico and
the southwestern U.S. Species of Pr. sect.
Porophyllum have thin, petioled leaves that
are filiform to broad, and are distributed in
South and Central America and in more
mesic regions of North America.
Two molecular studies have included
various Pectis and Porophyllum species.
Baldwin et al. (2002) analyzed the helenioid
Heliantheae using ITS data, and included
one species each of Pectis and Porophyllum.
Loockerman et al. (2003) used ITS and ndhF
sequences to infer relationships within
Tageteae and included six Pectis and four
Porophyllum species. Both studies suggested
a close relationship between Pectis and
Porophyllum but Loockerman et al. (2003)
found three Porophyllum species nested
within Pectis, calling into question the
monophyly of the two genera. However,
both analyses had very small sample sizes
and lacked strong support for their relationships. In the Loockerman et al. (2003) study,
Porophyllum tridentatum was strongly supported as being sister to Leucactinia bracteata and Urbinella palmeri, and thus a new
genus, Bajacalia, was erected for the three
taxa.
DECEMBER, 2016
CHROMOSOME NUMBERS IN PECTIS AND
POROPHYLLUM. The base chromosome number for Pectis is x 5 12 (Keil, 1977). Of the
54 Pectis species and varieties for which
chromosomes have been counted, 39 (72%)
are diploid and 15 are polyploid (Appendix
S2 in Supplemental Data with the online
version of this article). Eight species are
tetraploid, two of which (Pt. longipes and Pt.
repens) have been reported as having diploid
individuals as well. Six Pectis are hexaploid,
among them Pt. saturejoides, which has also
been reported as diploid. Pectis ericifolia is
the only octoploid reported in the genus.
Most Porophyllum species have a base number of x 5 12, but five species (Pr.
lanceolatum, Pr. macrocephalum, Pr. punctatum, Pr. ruderale and Pr. viridiflorum) have
been counted as x 5 11. Of these, Pr.
punctatum and Pr. ruderale have also been
reported with x 5 12 counts. Of the 14
Porophyllum species for which the ploidy
level is known, nine are diploids, four are
tetraploid and Pr. ruderale has been reported
with diploid, triploid, and tetraploid counts.
Porophyllum greggii is the only known
hexaploid in the genus.
PHOTOSYNTHETIC PATHWAY. C4 photosynthesis is a complex trait in which
anatomical, chemical and regulatory modifications reorganize the first steps of carbon
assimilation found in the C3 pathway. In C3
plants, the first enzyme involved in photosynthesis is Rubisco. In C4 photosynthesis,
the first enzyme is PEP-C. Rubisco discriminates more against C13 than PEP-C does,
and as a result, C4 plants have a higher
proportion of C13 than C3 plants. This
difference allows determination of the pathway used by a given plant by measuring the
proportion of C13 in a tissue sample.
Although C4 photosynthesis has arisen repeatedly and takes many different forms,
there is a phylogenetic component to its
distribution. The 65 C4 lineages occur in just
19 families (Sage et al., 2012). In the
Asteraceae, one of the largest families of
flowering plants, there are five C4 lineages
that occur in just two tribes: Coreopsidae (in
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
Chrysanthellum Pers., Glossogyne Cass., and
Isostigma Less. of subtribe Chrysanthellinae)
and Tageteae (in Flaveria Juss. of subtribe
Flaveriinae and in Pectis of subtribe Pectidinae). The C4 genera in Chrysanthellinae
form a monophyletic group and thus are
thought to represent a single acquisition of
the syndrome (Kimball & Crawford, 2004).
However, based on phylogenetic analysis, C4
photosynthesis is thought to have multiple
origins in Flaveria (McKown et al., 2005).
Muhaidat et al. (2007) included Pectis
glaucescens in their survey of C4 eudicots,
and reported its chemical subtype as NADPME and its Kranz type as atriplicoid. This
clustered phylogenetic distribution suggests
an underlying predisposition toward C4
photosynthesis in certain clades. An evolutionary change in a common C3 ancestor
might facilitate additional modifications
down the line and could explain multiple
origins of C4 among close relatives.
Just as there is a phylogenetic signal in
the occurrence of C4 photosynthesis, the
origin of the syndrome is clustered in
particular geographic areas as well. The
majority of New World C4 eudicot lineages
arose in North America (Sage et al., 2011).
The evolution of C4 lineages has been linked
to the Oligocene decline of atmospheric
CO2, but environmental factors such as heat,
drought, and fire regime may have played
a role (Osborne, 2011). Pollen records show
that C4 grasses began to dominate just 8-3
mya (Cerling, 1999) but only recently have
molecular studies allowed an estimate of the
timing of their origin. The rise of C4
photosynthesis in monocots is estimated at
32.0–25.0 mya for Chloridoideae (Christin
et al., 2008) and 10-20 mya for Cyperaceae
(Besnard et al., 2009). Portulaca is the oldest
known lineage of C4 eudicots, having diverged 6 30 mya (Ocampo & Columbus,
2010; Christin et al., 2011).
Much of our knowledge of the evolution
of C4 photosynthesis is from Flaveria (Engelmann et al., 2003; Westhoff & Gowik,
2004; McKown et al., 2005; McKown &
Dengler, 2007), which has both C3 and C4
species, as well as C3-C4 intermediates. The
modifications in C3-C4 intermediates are
thought to confer evolutionary benefits in
their own right, and may leave C3-C4
intermediates in a more or less stable state
of photosynthetic efficiency appropriate to
their environment, with no momentum
toward one or the other state. However,
the development of fully functional C4
photosynthesis involves as a series of modifications, from changes in leaf anatomy to
up-regulation and cell-specificity of C4
chemicals. C3-C4 intermediates may also
represent snapshots of the process of evolution toward full C4 photosynthesis, with
each state a precursor to full C4 functionality. With the benefit of a phylogeny to
determine ancestral vs. derived states, one
can trace anatomical and biochemical alterations that may predispose plants with intermediate traits to develop the full C4
pathway. This analysis has been done in
Flaveria (Engelmann et al., 2003; Westhoff &
Gowik, 2004; McKown et al., 2005; McKown
& Dengler, 2007) with the resulting acquisition path outlined in Sage (2003) and
Gowik and Westhoff (2011).
By expanding the focus to other C4
eudicots, we may see anatomical and physiological commonalities in the evolution of
the C4 syndrome. Such studies are continuing in Amaranthaceae (Kadereit et al., 2003;
Sage et al., 2007), Cleome (Brown et al., 2005;
Marshall et al., 2007), Heliotropium (Vogan
et al., 2007), and Molluginaceae (Christin
et al., 2010). Each lineage examined will offer
insights into C4 biology and evolution.
MATERIALS AND METHODS
TAXON AND MARKER SELECTION. Our
strategy was designed to sample as widely
as possible both Pectis and Porophyllum,
with the primary focus on Pectis. Roughly
230 names have been applied to various taxa
in Pectis, ca. two thirds of which are
considered taxonomic synonyms. Recent
treatments and floras were utilized when
deciding which species to include and which
9
10
LUNDELLIA
to treat as synonyms. For previously synonymized taxa that are wide-ranging, accessions from each region were included (when
possible) to assess whether molecular data
support their placement in synonymy. Since
no single treatment covers Pectis throughout
its range, Pectis species recognized by
Aristeguieta (1964), Bautista (1987), Cabrera
(1978), Jørgensen and León-Yánez (1999),
Keil (1975, 1977a, 1978, 1996), and Liogier
(1962, 1996, 2000) were sampled. Porophyllum species recognized by Johnson (1969)
and Turner (1996) were also examined.
Porophyllum tridentatum Benth., (5 Bajacalia tridentatum (Benth.) Loockerman, B.L.
Turner & R.K. Jansen was not included in
our analysis of Porophyllum, as the molecular analysis of Loockerman et al. (2003)
and cytological data (x 5 15) of Reveal &
Moran (1977) suggested it is not closely
related to the rest of Porophyllum.
Not all species were sampled, due either
to rarity in the field, paucity of herbarium
collections, or both. The final sampling
included 78 species and varieties of Pectis,
22 of Porophyllum, and one species each of
Chrysactinia A. Gray, Nicolletia A. Gray and
Tagetes L. as outgroups. Thus, approximately 75% of both Pectis and Porophyllum
species were included. Outgroups were
chosen based on relationships indicated in
Loockerman et al. 2003. Sampled taxa and
voucher information with GenBank numbers are listed in Appendix 1.
For the molecular analyses we used loci
that were 400-2,000 bases long and sufficiently variable to resolve relationships at the
species level. The internal transcribed spacer
(ITS) region of nuclear ribosomal DNA
(nrDNA) was included because of its prior
use in elucidation of sub-generic Asteraceae
relationships (Baldwin, 1993; Baldwin et al.,
2002) and ease of amplification from
herbarium material. The chloroplast (CP)
loci selected based on length and p-distance
between species (Shaw et al., 2007; Timme
et al., 2007; Hansen et al., 2009) were coding
regions matK and 3’ ndhF, and the CP noncoding areas rpl16 intron, trnL-rpl32 spacer,
DECEMBER, 2016
3’ trnV-ndhC spacer, 5’ trnY-rpoB spacer).
Primer and locus information are summarized in Appendix S1 (see Supplemental
Data with the online version of this article).
DNA ISOLATION, PCR AMPLIFICATION,
AND SEQUENCING. Total genomic DNA was
extracted from 6 20 mg of dried leaves
using Qiagen DNeasy Plant Mini Kits
(Qiagen, Valencia, California). Dilution of
the genomic DNA to 1:10 provided the best
amplification of both nuclear and chloroplast loci. PCR methods followed Loockerman et al. (2003). PCR products were
visualized under UV light in a 1.5% agarose
gel containing SYBR safe DNA gel stain
(Invitrogen, Carlsbad, CA, USA). Amplicons
were cleaned by adding 4.0% Shrimp
Alkaline Phosphatase and 1.0% Exonuclease
I to the PCR tube and heating to 37u C for
30 min followed by 80u for 15 min (Werle
et al., 1994), and sequenced using BigDye
(v.3.1) Terminator Cycle Sequencing (Applied Biosystems, Foster City, Ca, USA) at
the Institute for Cell and Molecular Biology
Core Facility, The University of Texas at
Austin.
PHYLOGENETIC ANALYSIS. Individual sequences were trimmed and edited using
Sequencher (Gene Codes CorPt., Ann Arbor,
Michigan), and contigs aligned with MacClade 4.08 OSX (Maddison & Maddison,
2005). If a particular accession would not
amplify for a certain locus, that region of the
combined dataset was coded as missing data.
All sequences are deposited in GenBank
(http://www.ncbi.nlm.nih.gov/genbank/), with
accession numbers listed in Appendix 1.
Because ITS sequences can present polymorphisms through hybridization, introgression, and incomplete lineage sorting (Alvarez
& Wendel, 2003), PCR products of some
accessions were cloned to test for variation
between and within species. Since cloning all
accessions was not feasible, only those
samples for which direct sequencing showed
evidence of polymorphisms (13 accessions)
were cloned. Successful amplifications were
visualized on an agarose gel and cloned using
the TOPO-TA cloning kit (Invitrogen,
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
Carlsbad, CA, USA). Ten colonies were
chosen from each plate and amplified using
the M13 plasmid primers provided in the
cloning kit. All 5.8S motifs were screened to
identify pseudogenes (Harpke & Peterson,
2008), and this resulted in the elimination of
a total of 5 clones.
Clone copies from the same accession
almost never appeared in separate wellsupported clades. For accessions that had
different clone copies, the clones were either
monophyletic or appeared with other related
species in polytomies (tree not shown).
Because the support for such clades was so
low, we did not believe any particular copy
to be more representative of a species than
any another copy, and so chose the clone
from the first of ten colonies selected from
each plate to include in the final analyses. An
exception, Pectis multiflosculosa, had two
clone copies in two distinct clades, so a copy
of each type was included in the ITS and the
combined CP+ITS analyses. The Pt. multiflosculosa CP sequence was duplicated and
added to each ITS clone sequence.
Before further analysis, duplicate samples of taxa for which the sequences were
identical across all loci were eliminated.
Sequence length of each locus and percentage of missing and parsimony-informative
(P.I.) characters are shown in Table 1.
The ITS and the combined CP datasets
were analyzed separately and together, using
maximum likelihood (ML) with RAxML
(Stamatakis, 2006) and Bayesian inference
(BI) with MrBayes 3.1.1 (Huelsenbeck &
Ronquist, 2001). All characters were weighted equally, character state transitions were
treated as unordered, and gaps were treated
as missing data.
RAxML allows for individual partitions
of a dataset to be run with their own model
of molecular evolution, including partitioning by codon position. The CP and CP+ITS
datasets were partitioned as follows: chloroplast non-coding, chloroplast coding (by
codon position), and ITS. The combined
partitions were run together under the same
GTR model, with parameters estimated
separately for each partition. Each analysis
was performed ten times from a random
starting tree, with 500 bootstrap replicates.
As the final likelihood values of each run
were very similar (within 0.003% of final
score), bootstrap replicates from each run
were combined to estimate support for the
tree with the best ML score. Clades with
bootstrap values above 70% are considered
well-supported (Hillis & Bull, 1993).
Prior to conducting the Bayesian analyses, the Akaike information criterion (AIC)
was used via Modeltest 3.7 (Posada and
Crandall, 1998) to determine the most
appropriate model of DNA sequence evolution for each of the seven loci. The results
were incorporated into the three analyses:
ITS, CP, and CP+ITS combined. Bayesian
analyses were performed using default priors,
with two simultaneous runs with four
Markov chains with heating values of 0.15,
0.2 (default), or 0.3, sampling every 100
generations. Each chain was run for at least
10 million generations and up to 20 million
generations, depending on how long it took
to reach stationarity (the average standard
deviation of split frequencies between runs
#0.01), and convergence was confirmed by
using AWTY graphical analysis (Wilgenbusch et al., 2004). Burn-in trees (30%) were
discarded, and the remaining trees and their
parameters saved. The frequency of inferred
relationships was used to represent estimated
posterior probabilities (PP). Clades with PP
$ 0.95 are considered strongly supported
(Wilcox et al., 2002).
HYPOTHESIS TESTING. Conflicting topologies between analyses of CP and ITS
datasets led to testing the results of each
analysis against the topology of the other.
Hypotheses of alternate topologies were
tested using the approximately unbiased
(AU) test (Shimodaira, 2002) implemented
in CONSEL (Shimodaira & Hasegawa, 2001),
comparing constrained vs. best trees from
500 RAxML bootstrap replicates. Specifically,
conflicts were addressed between the ITS and
the CP datasets regarding the placement of
three clades/taxa: Porophyllum amplexicaule
11
12
LUNDELLIA
TABLE 1. Statistics for datasets used including results from ML searches.
5’
trnKmatK
No. accessions sequenced
Aligned dataset (bp)
bp included in final
analysis
# Pt.I. chars.
(no outgps)
Missing data (incl gaps)
ML model selected (AIC)
Likelihood CI
Likelihood RI
Likelihood score (-ln)
156
70
47
4
n/a
n/a
n/a
n/a
n/a
matK-3’
trnK
3’
ndhF
ndhFycf1
156
1,488
1,488
156
347
234
152
822
594
152
228
61
64
15
45
5
n/a
TVM+G
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
TVM+G
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
matK
rpl16
trnLrpl32
3’
trnVndhC
5’
trnYrpoB
CP
ITS
CP+ITS
130
1,742
1,371
164
1,147
865
149
821
754
153
858
788
157
6,201
6,201
156
838
684
157
6,885
6,885
120
127
39
49
468
308
776
n/a
GTR+G+I
n/a
n/a
n/a
n/a
TVM+G
n/a
n/a
n/a
n/a
TVM+G
n/a
n/a
n/a
n/a
GTR+G
n/a
n/a
n/a
17.69%
n/a
0.697
0.905
18,348.32
5.53%
GTR+G+I
0.540
0.908
7,478.80
16.6%
n/a
0.521
0.854
27,363.46
DECEMBER, 2016
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
+ Pr. scoparium, Pectis linifolia + Pt. coulteri,
and Pt. papposa var. papposa. This was done
by analyzing the ITS dataset with RAxML
under a constraint of the CP topology, and
comparing the best topology under the
constraint with the best unconstrained topology recovered from the ITS dataset. A
reciprocal test was then conducted using the
CP dataset, comparing the best topologies
recovered from the CP dataset, both unconstrained and under the constraint of the
ITS topology.
MOLECULAR DATING. To infer divergence times, data were combined with
sequences from GenBank to create a dataset
of matK and 3’ ndhF sequences. This
included 21 sequences from the five major
Pectis clades recovered from the phylogenetic analysis, as well as several Porophyllum
and other species of tribe Tageteae. Data
from six of the 12 major Asteraceae clades
recovered in Panero and Funk (2008) were
included, for a total of 46 taxa. The
phylogeny was rooted on the branch leading
to Barnadesia and Doniophyton (Barnadesioideae), which is well-supported as sister
to the rest of Asteraceae (Jansen & Palmer
1987; Kim et al., 2005; Panero & Funk,
2008).
Modeltest 3.06 (Posada & Crandall,
1998) with the Akaike Information Criterion
was used to determine the most appropriate
model of sequence evolution for the dataset.
The Likelihood Ratio Test (LRT) was used to
determine whether the data satisfied the
assumptions of a molecular clock, with the
formula of LR 5 2*(lnL1-lnL2), where lnL1 is
the likelihood of the tree with a molecular
clock enforced, and lnL2 is the likelihood of
the tree without the clock constraint, and
degrees of freedom of n-2, where n is the
number of taxa (Felsenstein, 1988). The LRT
resulted in a significant difference between
the trees, so a Bayesian relaxed uncorrelated
lognormal molecular clock was used to
account for rate heterogeneity across lineages.
Not all lineages evolve at the same rate,
and when using molecular data to infer dates
for lineages, it is best to use multiple fossils
to constrain various nodes throughout the
tree to lessen the margin of error associated
with rate smoothing. Fossils provide only
approximate dates, can be difficult to
associate accurately with extant taxa, and
are necessarily younger than the lineage they
represent. Most paleobotanical evidence of
the Asteraceae is from fossil pollen, but
a macrofossil from Patagonia of 47.5 mya
was allied with the Mutisioideae (Barreda
et al., 2010). Although constraining a tree at
multiple nodes is best, due to the uncertainty of the relationships between some
Asteraceae subfamilies (Panero & Funk,
2008), only the node between the Barnadesioideae and the remainder of the Asteraceae
was constrained.
The aligned data matrix was analyzed
in BEAST 1.7.0 (Drummond & Rambaut,
2007) from an input file created in BEAUti
1.7.0 (packaged with BEAST). Two independent runs of 10,000,000 were conducted.
Settings were as follows: a substitution
model of GTR+G+I (based on Modeltest
results), with base frequencies estimated;
relaxed uncorrelated lognormal clock with
rates estimated; a Yule process speciation
tree prior with the starting tree randomly
generated; prior distributions were set at
default except for the ingroup. The node
separating Barnadesioideae from the rest of
the Asteraceae was calibrated based on the
Mutisioideae fossil date of 47.5 mya. Assuming the Barreda et al. (2010) fossil date is
a minimum age of the split, a lognormal
prior distribution with a mean of 2.0,
standard deviation of 0.5, and offset of
44.5 mya was applied. These settings provide
a 5% probability of 47.75 mya, set the
median probability at 51.89 MY, and a 95%
probability of 61.32 mya for the most recent
common ancestor (MRCA) of Barnadesioideae and the rest of the Asteraceae. Tracer
v1.5 (Rambaut & Drummond, 2007) was
used to assess convergence of the runs,
confirm an appropriate estimated sample
size, and determine the appropriate number
of burn-in trees. Tree information from each
run was combined with LogCombiner
13
14
LUNDELLIA
DECEMBER, 2016
(packaged with BEAST), with the first 20%
(2,000 trees) of each run discarded. A
maximum clade credibility tree was constructed with TreeAnnotator (packaged with
BEAST), and FigTree v1.3.1 (Rambaut,
2008) was used to visualize the estimations
of divergence dates on the tree.
CARBON ISOTOPE RATIOS. Since plants
differentially use carbon isotopes (C12 and
C13) depending on whether they use C3 or
C4 photosynthesis, the proportion of C13 in
leaf tissue can be used as a proxy for the type
of photosynthesis employed by that plant.
Because rubisco discriminates against C13,
C4 plants have a higher proportion of C13
than C3 plants. This proportion is expressed
as delta (L) in parts per thousand (%). The
metric LC13% is the difference between the
tissue sample reading and a reference reading. The reference used for C13 is Pee Dee
Belemnite (PDB), a Cretaceous marine fossil
(Belemnitella americana, {Belemnitellidae)
from the Pee Dee formation of South
Carolina. PDB has a C13/C12 ratio that is
higher than other natural samples. By
convention, this standard is set to zero, so
the amount of carbon measured in plants
and animals is expressed as a negative
number (Petersen & Fry, 1987). As C4 plants
have more C13 than C3 plants, their LC13%
signature (-15% to -10%) is higher than
that of C3 (-21% to -30%) plants (Cerling,
1999; Marchese et al., 2005), so LC13%
provides an indirect method for inferring C4
photosynthesis.
To infer the photosynthetic pathway for
each sample, 2 mg of plant tissue (stem or
leaves) were assayed for carbon isotope ratio
using an Integramass spectrometer with a PDB
standard. Carbon isotope ratios were determined by the University of California stable
isotope facility (http://stableisotopefacility.
ucdavis.edu).
RESULTS
CP DATASET. The final CP dataset
comprising all CP loci contained 157 accessions. The models indicated by Modeltest
were GTR+G+I for the rpl16 intron, GTR+G
for the 5’ trnY-rpoB spacer, and TVM+G for
the remaining four CP loci. As MrBayes does
not allow for the TVM submodel, GTR+G
was substituted for the Bayesian analysis.
Prior to combining the CP loci, areas of
ambiguous alignment were excluded from
each CP locus, with a total of 1,321 bases
excluded. The aligned dataset comprised
6,201 bp, and ten RaxML runs resulted in
a best tree of -ln 5 18,348.32 (Fig. 1A).
Table 1 provides a summary of loci and
dataset statistics.
ITS DATASET. The final ITS dataset was
reduced to those accessions for which
sequences for the chloroplast loci were
obtained. Because of uncertainty of the
alignment, 154 bases were excluded prior
to analysis. The final aligned dataset comprised 156 accessions of 684 bp. Ten RaxML
runs resulted in a best tree with a likelihood
score of -ln 5 7,478.80 (Fig. 1B). Table 1
shows a summary of results statistics for the
datasets.
CP+ITS DATASET. An incongruence
length difference (ILD) test indicated a significant conflict between the ITS and CP
datasets (p 5 0.02). However, visual inspection of the majority rule trees from ML
bootstrap and Bayesian analyses showed that
most of the conflicts were not well supported. The ILD test is thought to be very
conservative, falsely rejecting congruence
(Cunningham, 1997; Darlu & Lecointre,
2002) showed that when the ILD test
resulted in a p-value of greater than 0.01,
combining the datasets improved or did not
diminish phylogenetic accuracy. Therefore,
the CP and ITS datasets were combined. The
final CP+ITS dataset contained 157 accessions, with 6,885 aligned bp. Ten RaxML
runs of this dataset resulted in a best tree of
-ln 5 27,363.46 (Figs. 2-4).
PHYLOGENETIC ANALYSES—PECTIS. Analyses of the CP, ITS, and CP+ITS datasets
provide strong support for the monophyly
of Pectis. Figure 1 shows a comparison of the
CP and ITS topologies, and the topology
recovered from the combined CP+ITS
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
FIG. 1. Comparison of CP and ITS topologies. A: ML cladogram from CP dataset, ln 5
-18348.3266. B: ML cladogram from ITS dataset, ln. 5 -7478.8052. Branches in bold are well-supported
($ 70 bootstrap or $ 0.95 PP). Colors refer to Pectis clades A-E, PH5Porophyllum sect. Hunteria,
PP5Porophyllum sect. Porophyllum.
15
16
LUNDELLIA
DECEMBER, 2016
FIG. 2. ML cladogram from CP+ITS analysis, showing species of Pectis, with clades A-D colorcoded. ML bootstrap support is shown above branches, and Bayesian PP support is shown below. An
asterisk indicates support below 50% bootstrap or 0.95 PP. Thick-lined branches lead to well-supported
clades ($ 70 bootstrap, $ 0.95 P). ln 5 227363.4645. Phylogram of same analysis appears below
the cladogram.
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
FIG. 3. ML cladogram from CP+ITS analysis, showing species of Pectis clade E.
17
18
LUNDELLIA
DECEMBER, 2016
FIG. 4. ML cladogram from CP+ITS analysis, showing Porophyllum species, collection site, and
sectional affiliations.
dataset is shown in Figs. 2 and 3 (Pectis) and
Fig. 4 (Porophyllum). All datasets recover
five well-supported clades within Pectis
(clades A-E, Fig. 1). The CP and ITS differ
in their placement of either clade A (ITS) or
clade B (CP) as sister to the rest of the genus.
In all analyses, the remainder of the genus is
split between two well-supported Sonoran
and Chihuahuan Desert clades (C and D in
Fig. 1) and a large clade (E) with species that
occur from central Mexico to San Luis,
Argentina.
PHYLOGENETIC ANALYSES—POROPHYLLUM. The inclusion of 22 of roughly 30
Porophyllum species allowed conclusions to
be made regarding the relationships of
Porophyllum to Pectis and within Porophyllum. The results suggest that Pr. amplexicaule and Pr. scoparium do not belong to
Porophyllum (sensu Johnson, 1969). They
form a strongly-supported clade that is the
sister-group to a combined Pectis+Porophyllum clade. Porophyllum filiform and Pr.
greggii form a well-supported clade sister to
the rest of Porophyllum, which appears as
a grade of clades (Fig. 4). Pr. sect. Hunteria
and Pr. sect. Porophyllum are not recovered
as monophyletic.
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
HYPOTHESIS TESTING. The CP and ITS
datasets provided incongruent results in
three groups of note: Pectis imberbis + Pt.
linifolia (clade A), Pt. papposa var. papposa,
and Porophyllum amplexicaule + Pr. scoparium. Reciprocal AU tests were performed to
assess whether, given a dataset, there was
a significant difference in likelihoods between the best tree obtained from that
dataset and the alternative topology (the
constraint) obtained from the other dataset.
The constraint topologies and results are
shown in Fig. 5.
The ITS topology (Fig. 1B) shows clade
A (Pectis imberbis+Pt. linifolia) as a sister
group to the rest of the genus, followed by
clade B (Pt. coulteri + Pt. multiseta). These
relationships are swapped in the CP dataset,
which recovers clade B sister to the rest of
Pectis, and clade A appearing next in the
grade (Fig. 1A). The latter relationship is not
strongly supported (59% ML bootstrap and
0.67 Bayesian PP support), and the AU test
shows that, when using the CP dataset, the
best CP topology is not significantly better
than the best ITS topology. The CP+ITS
dataset strongly supports the position of
clade A as sister to the rest of the genus.
Pectis papposa var. papposa groups with
Pt. vollmeri in the topology suggested by the
CP dataset (Clade C of Fig. 1A). However,
the ITS topology (Fig. 1B) shows Pt. papposa
var. papposa grouped in Clade D with Pt.
filipes var. subnuda and Pt. barberi. Given the
ITS dataset, the CP topology can be rejected;
likewise, given the CP dataset, the ITS
topology can be rejected. The CP+ITS
dataset strongly supports the position of
Pt. papposa var. papposa in clade C with Pt.
vollmeri.
The CP dataset recovered a clade of
Porophyllum amplexicaule+Pr. scoparium at
the base of Pectis+Porophyllum (Fig. 1A),
whereas the ITS dataset showed this clade to
be sister to the rest of Porophyllum (Fig. 1B).
Given the ITS dataset, the CP topology
cannot be rejected, but given the CP dataset,
the ITS topology can be rejected. In the
combined CP+ITS dataset, Pr. amplexicaule
and Pr. scoparium are well-supported as
sister to the combined Pectis+Porophyllum.
PHYLOGENETIC DISTRIBUTION OF POLYPLOIDS. In Pectis, most of the known
polyploids occur in the more terminal clades
(Appendix S3, see Supplemental Data with
the online version of this article). Clade E4
(Fig. 3) contains five polyploid species, clade
E1 has three, and clades D and E3 both
have one. Two of the four taxa in clade E2
(tetraploid Pt. repens and hexaploid Pt.
saturejoides) have reports of both diploid
and polyploid counts. In two cases (Pt.
latisquama and Pt. multiflosculosa), the
polyploid species appears sister to a diploid
species, but most polyploids in the genus are
sister to taxa for which the chromosome
number is unknown. The four known polyploid Porophyllum species included in this
study occur in separate clades throughout
the genus. The combined CP+ITS dataset
places the hexaploid Pr. greggii with Pr.
filiforme (chromosome number unknown),
which together are sister to the rest of
Porophyllum.
One internal Porophyllum clade comprises all x 5 11 taxa, together with one x 5
12 (Pr. coloratum) and several for which the
chromosome numbers are not known.
MOLECULAR DATING. The dataset of
matK (1,902 bp) and 3’ ndhF (603 bp)
sequences comprised 2,505 characters and 46
taxa. The maximum clade credibility tree
recovered most clades with greater than 0.95
PP (Fig. 6). The BEAST analysis showed
Tageteae and Helianthus diverging 26.55
(19.23–33.73) mya. The MRCA of Tageteae
is 24.34 mya, but this node has just 0.92 PP
support. Porophyllum amplexicaule diverged
from Pectis + Porophyllum at 15.92 MYA
(11.03–21.53). The divergence of Pectis and
Porophyllum s.s. is estimated at 11.27 (7.56–
15.58) mya, and divergence within Pectis
began 9.12 (5.75–12.61) mya but most of the
nodes split within the last 5 my.
CARBON ISOTOPE ANALYSIS. We obtained
L13C% values for 80 Pectis and Porophyllum
species, as well as Tagetes erecta. All Pectis
accessions have L13C% values consistent
19
20
LUNDELLIA
DECEMBER, 2016
FIG. 5. Reciprocal tests of alternate topologies. Figures on the left (1A, 1B, 1C) show the topologies
recovered with the CP dataset, and figures on the right (2A, 2B, 2C) show the topologies recovered with
the ITS dataset. *p-values of $ 0.05 indicate that the topology shown has a significantly lower likelihood
than the best tree recovered using that dataset.
with C4 photosynthesis (-15.60% to
-10.70%, mean 5 -13.14%), and all Porophyllum accessions have values consistent
with C3 photosynthesis (-30.65% to
-22.90%, mean 5 -27.64%). Tagetes erecta
has a L13C value of -30.37%. The frequency
distribution of the L13C values is presented
in Fig. 7, and the average L13C value for each
species, including previously reported data
from species not surveyed by us, is shown in
Table 2. Voucher information is given in
Appendix 1.
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
FIG. 6. Chronogram of the maximum clade credibility tree estimated from matK+3’ndhF
sequences using BEAST. Horizontal bars are the 95% highest probability density (HPD) for the age of
that node (green bars are on Porophyllum nodes, yellow bars are on Pectis nodes). Nodes with HPD bars
have PP support of $ 0.95. Nodes without HPD bars have ,0.95 PP. Mean ages are shown for clades
mentioned in the text. A partial timescale is shown at the bottom, with units in millions of years. Epoch
dates follow The Geological Society of America (GSA, 2009).
21
22
LUNDELLIA
DECEMBER, 2016
FIG. 7. The frequency distribution of carbon
isotope ratios for the species listed in Table 2. All
Pectis species sampled have ratios consistent with
C4 plants, all Porophyllum species sampled have
ratios consistent with C3 plants.
DISCUSSION
Pectis species have traditionally been
considered a natural, morphologically distinctive group (Strother, 1977). However,
molecular analysis of the Tageteae (Loockerman et al., 2003) showed Pectis linifolia as
sister to the combined Pectis+Porophyllum,
based on a combined ITS+ndhF dataset. By
expanding the dataset to 6,201 bases of CP
loci and more taxa, a well-supported and
monophyletic Pectis is recovered as sister to
Porophyllum. The combined CP+ITS dataset
suggests that two Porophyllum species, Pr.
amplexicaule and Pr. scoparium, fall outside
of the genus, and are sister to the combined
Pectis+Porophyllum. Porophyllum amplexicaule is restricted to southwestern Coahuila,
and Pr. scoparium can be found in desert
scrub from southern New Mexico, southeast
into southwest Texas, and into Mexico from
Coahuila to Nuevo Leon. Johnson (1969)
suggested that Pr. amplexicaule and Pr.
scoparium hybridize where they co-occur.
Both are suffruticose perennials up to 60 cm
high and have yellow corollas (vs. the green,
purple or off-white corollas of most of
the genus).
Pectis clades A through E (Fig. 1) generally correspond to geographic distribution;
however, a few members are widespread.
Clades A and B (Fig. 2) are generally associated with the Sonoran desert. However, Pectis
linifolia var. linifolia of clade A has the largest
natural range of the genus. Some of its
distribution (the Galapagos and Hawaiian
Islands) is probably due to recent introductions (Wiggins & Porter, 1971; Wagner et al.,
1990), but its natural range spans from
Arizona to Bolivia, with a large disjunct region
between Guatemala and Colombia. It is also
found throughout the Caribbean islands. Keil
(1978) suggested that Pt. linifolia var. linifolia
is autogamous, and that this breeding system,
combined with its stiff, recurved awns suited
for animal dispersal, contribute to its success
as a colonizer. In contrast, Pectis linifolia var.
hirtella has a very small range, and is endemic
to the Mexican states of Guerrero and
Michoacan. Both taxa are taller than most
Pectis species, and are often erect, with long
internodes and sparse, linear leaves.
Pectis coulteri and Pt. multiseta of clade B
(Fig. 2) are both low growing annuals with
distinctive antrorsely-barbed pappus awns.
Pectis coulteri is endemic to the mainland
Sonoran desert, whereas Pt. multiseta is
endemic to the Baja California Peninsula.
Clade C (Fig. 2) is composed of low-growing
annuals that are mostly associated with the
Sonoran and Chihuahuan deserts, but the
range of Pt. angustifolia extends from
southeast Wyoming to Chihuahua, Mexico,
and Pt. papposa extends into central Sinaloa.
Clade D species (Fig. 2) are annuals and
perennials associated with several different
habitats, from the Sonoran desert, foothills
of the Sierra Madre Occidental, and the
thorn scrub and coastal savannahs of Sonora
and Sinaloa. Clade E (Fig. 3) species are
diverse and cover a broad geographic area,
essentially mirroring the geographic and
morphological range of the whole genus.
Aside from Pt. linifolia, all the Caribbean and
South American species of Pectis are in this
clade. The CP dataset provides support for
four clades within clade E (Fig. 3), and
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
TABLE 2. Photosynthetic pathways in Pectis and Porophyllum. Data are the average L13C value for
each species (sample size if N.1). Average L13C value for Pectis 5 -13.14%; Average L13C value for
Porophyllum 5 -27.64%. All values are newly reported here unless indicated with an asterisk (*). See
Appendix 1 for voucher information.
Species
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
Nicolletia edwardsii*
Pectis amplifolia
Pectis angustifolia var. angustifolia
Pectis arida
Pectis barberi
Pectis berlandieri*
Pectis bonplandiana
Pectis brachycephala
Pectis brevipedunculata
Pectis cajamarcana
Pectis canescens*
Pectis ciliaris
Pectis coulteri
Pectis cubensis
Pectis cylindrica
Pectis decemcarinata
Pectis depressa*
Pectis diffusa
Pectis elongata var. floribunda
Pectis elongata var. fasciduliflora
Pectis elongata var. oerstediana
Pectis ericifolia
Pectis exilis
Pectis exserta
Pectis filipes*
Pectis gardneri
Pectis glaucescens
Pectis graveolens
Pectis haenkeana
Pectis holochaeta var. cana
Pectis holochaeta var. holochaeta*
Pectis humifusa*
Pectis imberbis
Pectis incisifolia*
Pectis latisquama*
Pectis leavenworthii
Pectis leonis
Pectis liebmannii
Pectis linearifolia
Pectis linearis
Pectis linifolia var. linifolia
Pectis longipes
Pectis luckoviae
Pectis monocephala
Pectis multiceps
Pectis multiflosculosa
Pectis multiseta var. ambigua*
Pectis odorata
Pectis oligocephala
L13C %
-26.50
-15.00
-14.10
-13.70
-13.41
-11.2
-15.30
-14.40
-13.00
-14.40
-11.4
-11.79
-13.51
-13.25
-15.60
-14.47
-11.7
-12.15
-13.03
-13.10
-12.80
-12.00
-13.93
-12.96
-11.4
-12.80
-12.85
-13.90
-15.10
-12.55
-11.0
-11.3
-14.25
-12.6
-12.5
-13.43
-12.05
-15.98
-12.63
-11.66
-11.60
-12.85
-14.24
-11.30
-13.40
-11.90
-13.05
-13.00
-13.24
(2)
(4)
(2)
(2)
(2)
(4)
(2)
(4)
(2)
(2)
(2)
(2)
(4)
(2)
(2)
(2)
(2)
(2)
(2)
(4)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.
81.
82.
83.
84.
85.
86.
87.
88.
89.
90.
91.
92.
93.
94.
95.
96.
97.
98.
Species
L13C %
Pectis papposa var. papposa*
Pectis peruviana
Pectis portoricensis
Pectis pringlei
Pectis propetes
Pectis prostrata*
Pectis pumila
Pectis purpurea
Pectis pusilla
Pectis pygmaea
Pectis repens*
Pectis rusbyi
Pectis saturejoides
Pectis sessiliflora
Pectis sinaloensis
Pectis stella
Pectis cf. stenophylla var. rosei
Pectis stenophylla var. stenophylla
Pectis subsquarrosa
Pectis substriata
Pectis tenuicaulis
Pectis tenuifolia
Pectis uniaristata var. holostemma*
Pectis uniaristata var. uniaristata
Pectis vandevenderi
Pectis vollmeri
Porophyllum amplexicaule
Porophyllum angustissimum
Porophyllum calcicola
Porophyllum coloratum var. coloratum
Porophyllum coloratum var. obtusifolium
Porophyllum filiforme
Porophyllum gracile*
Porophyllum greggii
Porophyllum lanceolatum
Porophyllum leiocarpum
Porophyllum linaria
Porophyllum lindenii
Porophyllum linifolium
Porophyllum macrocephalum
Porophyllum maritimum
Porophyllum pausodynum
Porophyllum punctatum
Porophyllum cf. ruderale
Porophyllum scoparium*
Porophyllum viridiflorum
Porophyllum zimapanum
Tagetes erecta
-11.5
-13.65 (2)
-14.15 (2)
-13.45 (2)
-13.70 (2)
-10.7 (3)
-13.97 (3)
-15.39 (5)
-13.50 (2)
-11.90
-12.1
-14.35 (2)
-12.65 (3)
-13.80
-13.10 (2)
-13.45 (2)
-14.11
-13.71
-12.50 (2)
-13.85 (2)
-11.90 (2)
-14.10
-11.3
-12.91 (2)
-15.15 (2)
-14.95 (2)
-24.85 (2)
-28.05 (2)
-28.90 (2)
-25.50
-29.00
-25.95 (2)
-27.01
-27.80 (2)
-29.50 (2)
-28.43 (2)
-28.75 (2)
-29.15 (2)
-29.30
-30.65 (4)
-27.20 (2)
-25.60 (2)
-29.48 (4)
-30.6
-22.9
-27.10 (2)
-26.75 (2)
-30.37 (2)
23
24
LUNDELLIA
DECEMBER, 2016
FIG. 8. Taxonomic classifications in Pectis. Cladogram from Fig. 2 with classifications mapped onto
the tree. Taxa with two colors were placed into two separate categories under different names but are
now considered synonyms. Column 1 shows the genera of Lorentea, Pectidium, Pectidopsis and Pectis at
the time that Gray described the former three as sections of Pectis. Thick-lined branches lead to wellsupported clades ($ 70 bootstrap, $0.95 PP).
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
suggests several species-pairs. The ITS dataset
does not show support for the large clades of
the CP topology, but does suggest several
smaller clades within clade E, as well as
species-pair affinities in common with the
CP topology. The combined CP+ITS dataset
recovers several clades and species-pairs with
strong support (Fig. 3).
INFRAGENERIC RELATIONSHIPS WITHIN
PECTIS. Six subgeneric divisions have been
recognized in Pectis, variously treated as
subgenera or as sections. Figure 8 shows the
CP+ITS cladogram with these divisions
mapped onto the tree according to the
revisions of Gray (1852), Fernald (1897)
and Keil (1975, 1977a, 1978).
Gray’s (1852) Pectis sect. Eupectis was
proposed to include species having uniseriate,
paleate, or broad-based and chaffy awns.
Aside from Pt. prostrata, which he described
in the same publication, Gray did not detail
which species were to be included in his
section Eupectis, and the species in column 1
of Fig. 8 are the species of Pectis recognized
by de Candolle at the time. In the same 1852
treatment, Gray transferred Pectidium punctatum Less. into Pectis, placing it under Pt.
sect. Pectidium. Pectis punctatum is synonymous with Pt. linifolia, which was, at the time,
in Pt. sect. Eupectis. After the designation of
Pt. linifolia (of former Pt. sect. Pectidium) as
the type of Pectis (Britton & Millspaugh,
1920), Pt. sect. Pectidium de facto became Pt.
sect. Pectis. The species variously recognized
within section Eupectis by Fernald or Gray
have not been treated since, and do not form
a monophyletic group in any of our analyses.
Pectis sect. Heteropectis, comprising
Pectis coulteri and Pt. multiseta (sensu Gray
1852, Fernald, and Keil), is recovered as
a well-supported clade (Clade B of Figs. 2,
8). Members of this section (Figs. 2, 8 clade
B) are restricted to the Sonoran Desert of
Baja California and mainland Mexico.
Pectis sect. Pectis (5 Pt. sect Pectidium
Less. sensu Fernald, and later, Keil), is well
supported and monophyletic (Clade A
Figs. 2, 8). Pectis sect. Pectis has two species,
Pt. imberbis and Pt. linifolia (the type of
Pectis). Both are tall, erect plants with sparse,
cylindrical leaves and elongated internodes.
This section (Figs. 2, 8 clade A) includes Pt.
imberbis, a rare species of southern Arizona
and northern Sonora region, and Pt. linifolia. Pectis linifolia is divided into two
varieties. Pectis linifolia var. hirtella is
a narrow endemic of Guerrero and Michoacan, Mexico, and Pt. linifolia var. linifolia is
a weedy species widely distributed throughout Pectis’ range.
Pectis sect. Lorentea has a complicated
history. In 1797, the genus Lorentea was
described by Ortega, and referred to a plant
that was later identified as a member of the
genus Sanvitalia. In 1816, Lagasca published
the name Lorentea for species of Pectis that he
considered separate from Pectis. The type of
Lorentea Lag. was based on a specimen of
Pectis prostrata Cav. from Cuba (this specimen was later identified as Pt. humifusa Sw.).
In 1830, Lessing segregated a group of Pectis
species into a new genus, for which he also
used the name Lorentea. Lorentea Lag. and
Lorentea Less. were both superfluous, but in
practice, both names were used. Gray (1852)
described section Lorentea A. Gray for species
of Pectis with a biseriate pappus and a ray
pappus sometimes greatly diminished or
absent. He did not specify which species
would be included. Schultz Bipontinus (Seemann et al., 1852) followed Gray’s suggestion
that Lorentea sensu Lessing was best included
with Pectis, and transferred the Lorentea of de
Candolle (1836) and Gardner (1846) into
Pectis (Seemann et al., 1852). Although Keil
(1977b) mentioned several species as members of Pt. sect. Lorentea, to our knowledge
no one has treated the section with a listing of
the species to be included. Those noted as
“Lorentea” in Fig. 8 are the Lorentea species
known at the time that Gray described Pt.
section Lorentea.
The sole member of Gray’s original
Pectis subg. Pectidopsis was Pt. angustifolia
(Gray, 1849). Gray later added Pt. filipes and
Pt. uniaristata. Fernald followed Gray’s
definition of Pectidopsis as those Pectis
species with a pappus that is coroniform or
25
26
LUNDELLIA
has a few slender but rigid, scabrid awns.
Fernald (1897) expanded the subgenus to
include 12 taxa, which do not form a monophyletic group in the combined CP+ITS
analyses (Appendix S4).
Fernald followed Gray’s 1884 expanded
definition of Pectis sect. Pectothrix as a taxon
with a pappus (of the disc florets, if not the
ray florets) of many equal or unequal
bristles, which are often broad at the base,
but not true scales. Neither Gray’s nor
Fernald’s concept of section Pectothrix forms
a monophyletic group in our analyses. On
the contrary, their species appear scattered
throughout the tree. However, all members
of clade C correspond to Pt. sect. Pectothrix
sensu Keil (1977a), with additional members
of Keil’s Pt. sect. Pectothrix found in clade D
(Figs. 2, 8). Pappus morphology therefore
seems to be homoplastic in Pectis.
Most species of clades C and D (Figs. 2,
8) occur in or adjacent to the Sonoran and
Chihuahuan Deserts, and clade E contains
many species of the Pacific Slope of Mexico,
as well as those of South America and the
Caribbean.
SECTIONAL RELATIONSHIPS WITHIN POROPHYLLUM. Results from our analyses suggest
that the primary characters used to designate
the sections of Johnson (1969), i.e., leaf
morphology and habitat, do not define
clades in Porophyllum. The species relationships show that the genus does not consist of
two clades, which correspond to the two
sections (Fig. 1). Geography correlates better
with relationship, with Sonoran and Chihuahuan species at the base of the tree and
southern Mexico-Central American and
South American species forming the derived
clades. Of the roughly eight South American
species, four out of the five sampled form
a well-supported clade. The fifth is Pr.
ruderale, a variable species of tropical North
and South America that is sister to the
Honduran accession of Pr. macrocephalum,
nested within the Pr. macrocephalum clade.
Johnson (1969) subsumed over 20 described
species and varieties into the single, widespread and variable Pt. ruderale, with two
DECEMBER, 2016
subspecies, Pr. ruderale subsp. macrocephalum and Pr. ruderale subsp. ruderale. He
used Pr. ruderale subsp. macrocephalum to
refer to what he called the “northern” taxa
(SW U.S. to northern Brazil, southern Peru,
and Bolivia), and Pr. ruderale subsp. ruderale
to refer to the “southern” taxa (Costa Rica
and the West Indies south to southern Peru,
through Brazil into northern Argentina). He
noted that in northern South America,
intermediate forms were common where
the two taxa were sympatric. Porophyllum
leiocarpum, endemic to Puerto Rico, was
originally described by Urban as a variety of
Pr. macrocephalum but was elevated to
specific status by Rydberg and has been
treated as such by subsequent authors
(Rydberg, 1916; Johnson, 1969; McVaugh,
1984). In our analyses, we have followed
Turner’s (1996) morphological criteria in
designating the Mexican and Central American taxa as Pr. macrocephalum, and the
South American accession as Pr. ruderale.
Although intermediate forms surely exist,
Turner noted that Pr. macrocephalum has
large heads on more stout peduncles and is
diploid, whereas Pr. ruderale has small heads
on slender peduncles, and is tetraploid.
Ecuadorian and Brazilian Pr. ruderale have
been reported as n 5 22, 23, 24, 34, 35 and
36 (Turner et al., 1979; Robinson et al.,
1981; Carr et al., 1999) but Dillon et al.
(1982) reported n 5 12 for a Peruvian
accession. Therefore, although only diploid
(n 5 11) specimens of Pr. macrocephalum
have been found in Chiapas (Strother, 1983)
and Arizona (Keil & Pinkava, 1976), Pr.
ruderale of South America has diploid and
tetraploid (and possibly hexaploid) members. The North and Central American
accessions (Pr. macrocephalum) have distinctly more ovate-oblong leaves, whereas
the South American accessions (Pr. ruderale)
have leaves that are linear-lanceolate. The
accessions of Pr. macrocephalum, Pr. ruderale
and Pr. leiocarpum form a well-supported
clade, with the Central American accession
of Pr. macrocephalum sister to the Pr.
ruderale from Ecuador (Fig 4). Porophyllum
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
ruderale from Brazil appears in a clade with
Pr. angustissimum, Pr. lanceolatum, and Pr.
linifolium. Hind (2002) has noted that
Porophyllum of Brazil and Argentina may
be under collected, and that there could be
diversity in the genus that has, in these areas,
been overlooked.
POLYPLOIDY IN PECTIS. Roughly 40% of
the known polyploids in Pectis occur on
islands. Just nine of the 620 Pectis species
that grow in the Caribbean or the Galapagos
Islands have been examined in cytological
studies, and of these, three are diploids, and
six are polyploids. Thus while polyploids
comprise 18% of the total Pectis species, they
comprise 77% of the island species (Appendix S2). This pattern is also seen in Hawaii,
where 80% of the native plants are polyploid
(Carr, 1988). While these ratios could
change if more Pectis species were sampled,
there is no reason to think that the current
sampling of cytological data is skewed
toward diploid or polyploid taxa.
Two mechanisms are often proposed to
explain why islands may be rich in polyploid
species. The first is that there is a general
trend toward self-fertilization in polyploids
(Barringer, 2007) and autogamy is often
proposed as one of the catalysts for a widespread distribution or successful colonization (Baker, 1955). However, the trend is not
clear for the Asteraceae, which has sporophytic self-incompatibility (SSI). The breeding systems of most Pectis species are
unknown, but Keil (1978) reported that Pt.
cylindrica, a tetraploid, and Pt. prostrata,
a diploid, are autogamous. A second explanation for the high occurrence of polyploidy
on islands is that successful establishment
favors plants with high genetic diversity
(Carr, 1988) sometimes associated with
polyploidy. Finally, many species in the
Asteraceae have SSI systems that allow
occasional self-fertilization. The ability to
self-pollinate increases the odds of reproducing after a colonizing event.
Our results showed that all species of
Pectis appear to use C4 photosynthesis (see
below). Genome duplication is one of the
preconditioning events proposed for a transition from C3 to C4 photosynthesis (Monson, 2003). Although 28% of the known
species of Pectis are polyploid, these species
are not at the base of the tree (Appendix S3).
The four known independent origins of C4
photosynthesis in the Asteraceae all occur
within the Helianthoideae supertribe, in
a group called the phytomelanic cypsela
clade. Barker et al. (2008) found evidence for
at least two paleopolyploidy events in the
history of the Asteraceae—one at the base of
the family, and another in a lineage that
eventually gave rise to Helianthus. They also
found that genes related to cellular organization are overrepresented in the paleologs
of the Asteraceae. Although these genome
duplications may have allowed for novel
functions that eventually gave rise to C4
photosynthesis in the this group, the scarcity
of C4 lineages in the Asteraceae shows that
many other conditions must be required.
ORIGIN AND EXTENT OF C4 PHOTOSYNTHESIS. After Smith and Turner (1975)
surveyed 20 Pectis and one Porophyllum
species, it was suggested that all Pectis
species were C4, and all Porophyllum (and,
in fact, the remainder of the Tageteae) were
C3. However, the closely-related Flaveria has
just 21 species yet shows great variation in
photosynthetic pathway, suggesting that
similar variability might exist in Porophyllum
(,25spp.) or Pectis (,90 spp.). The L13C%
values reported here appear to confirm that
C4 photosynthesis does not occur in Porophyllum. Furthermore, the switch from C3
to C4 appears to have happened after the
generic split between Pectis and Porophyllum, as all Pectis have L13C% values indicative of C4 photosynthesis.
North America is one of the hotspots of
origin for C4 photosynthesis (Sage et al.,
2011), and the North American C4 lineages
for which divergence times have been
estimated have appeared since the mid-late
Miocene: 13 mya for Tidestromia, 6.1 mya
for Allionia, 4.7 mya for Boerhavia, and
3.1 mya for Flaveria (Christin et al. 2011).
The anatomical preconditioning that may
27
28
LUNDELLIA
facilitate C4 photosynthesis must be selected
for, and in general, warm and dry environmental conditions are thought to make
such adaptations more advantageous. Did
Pectis evolve in such an environment? Keil
(1978) suggested that the ancestors of Pt.
sect. Pectis diverged in the Mexican Highlands. Porophyllum amplexicaule and Pr.
scoparium, sister to the rest of Pectis+
Porophyllum, are Chihuahuan desert species.
The basal species within Pectis are distributed mostly in north and central Mexico from
sea level to 800 m; Pt. sect. Pectis (Pt.
imberbis and Pt. linifolia, clade A of Fig. 2) is
sister to the rest of Pectis. Pectis imberbis is
endemic to the Sonoran and Chihuahuan
desert areas at the U.S./Mexico border, and
Pt. linifolia var. hirtella is endemic to the
Mexican states of Michoacan and Guerrero.
After Pt. sect. Pectis, the next diverging clade
(Pt. sect. Heteropectis) is endemic to the
Sonoran Desert. Fossil evidence shows that
the general drying trend since the late
Miocene led to a flora of increasing tolerance
to aridity, with an altitudinal fluctuation
during the pluvial stages of the Pleistocene
(Axelrod, 1979; Spaulding et al., 1983). The
uplift of the Sierra Madre Occidental and
Transvolcanic Belt further increased aridity
by providing rain shadows. Becerra (2005)
suggested these ranges provided a barrier to
the northern cold fronts, thereby allowing
the development of cold-intolerant taxa
10-20 mya. Although mesic woodlands
existed in the present-day desert regions
during the pluvial periods of the Pleistocene,
evidence from pack-rat middens suggests
that pockets of arid refugia persisted
throughout these periods (Elias et al., 1995;
Van Devender, 2000).
Our BEAST analysis recovers a mean
date of ,11 mya for the common ancestor of
Pectis and Porophyllum (Fig. 6), and given the
geographic distributions of the basal species
of the genera, we can surmise that they
diverged in Central/Northern Mexico. Thus,
C4 photosynthesis in this lineage evolved in
an area that was increasingly warm and dry,
with a pattern of summer monsoon. Sage and
DECEMBER, 2016
colleagues (2011) suggested that these are the
environmental conditions that would increase photorespiration in C3 lineages, setting
the stage for a fitness advantage to C3-C4
intermediacy.
SUMMARY
By sampling widely in both Porophyllum and Pectis, we have shown that Pectis is
monophyletic and sister to a clade containing the majority of the 7 Porophyllum
species. Just two recognized Pectis sections
are monophyletic, and neither of the two
Porophyllum sections is monophyletic. Porophyllum amplexicaule and Pr. scoparium are
sister to the Pectis+Porophyllum clade, and
should be treated as members of a new
genus. Within Pectis, the Caribbean and
South American species are in the more
derived clades that also contain most of the
polyploids of the genus. The evolution of C4
photosynthesis in Pectis occurred at or after
the initial divergence of Pectis and Porophyllum, in the late Miocene. In the time
since they diverged, Porophyllum has diversified into ,25 species, whereas Pectis
comprises at least 90 species. Perhaps the
acquisition of the full C4 syndrome fueled
the success and relatively rapid diversification of the Pectis, the largest genus of the
marigold tribe.
ACKNOWLEDGEMENTS
The authors thank Dave Cannatella, José
Panero, Stan Roux, and the anonymous
reviewers for providing valuable comments
on earlier drafts of the manuscript. We thank
the following colleagues for field-collecting
assistance: Les Landrum and Liz Makings at
Arizona State University; Tom Van Devender
and Anna Lilia Reina in Sonora and Sinaloa,
Mexico; Teodoro Clase and Alberto Veloz at
The National Botanic Garden of Santo
Domingo, Dominican Republic; Oscar Hinojosa and Enrique Ortiz at Universidad
Nacional Autónoma de México, Mexico
City. For general herbarium assistance, we
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
thank Tom Wendt and Lindsay Woodruff at
the Plant Resources Center at The University
of Texas at Austin. For providing specimen
loans and/or permission to sample leaf
material, we thank the following herbaria:
ARIZ, GH, LPB, MEXU, MO, NYGB, TEX/
LL, and US. We thank Tammy Sage for
assistance with preliminary anatomical studies. This research was supported in part by
a Doctoral Dissertation Award (DEB
0808388) from the National Science Foundation to DRH, multiple grants from The
University of Texas at Austin Graduate
Program in Plant Biology to DRH, the
Lundell Chair of BBS, and the S.F. Blake
Professorship to RKJ.
LITERATURE CITED
Abbott, R. J., A. C. Brennan, J. K. James, D. G.
Forbes, M. J. Hegarty, and S. J. Hiscock. 2009.
Recent hybrid origin and invasion of the British
Isles by a self-incompatible species, Oxford ragwort
(Senecio squalidus L., Asteraceae). Biological Invasions 11: 1145–1158.
Albers, C. C. 1942. Thimole in the volatile oil of Pectis
texana Cory. Pharmaceutical Arch. 13: 29–31.
Alvarez, I., and J. F. Wendel. 2003. Ribosomal ITS
sequences and plant phylogenetic inference. Molec.
Phylogen. Evol. 29: 417–434.
Aristeguieta, L. 1964. Flora de Venezuela. Vol. 10, pt. 2
Compositae. Instituto Botanico, Caracas.
Asprey, G. F., and Pt. Thornton. 1953. Medicinal
Plants of Jamaica. Part I. West Indian Medical J. 2:
1–86.
Axelrod, D. I. 1979. Age and origin of Sonoran Desert
vegetation. Occas. Paps. Calif. Acad. Sci. 132: 1–74.
Baker, H. G. 1955. Self-compatibility and establishment after ‘long-distance’ dispersal. Evol. 9:
347–348.
Baldwin, B. G. 1993. Molecular phylogenetics of
Calycadenia (Compositae) based on its sequences
of nuclear ribosomal DNA: chromosomal and
morphological evolution reexamined. Amer. J.
Bot. 80: 222–238.
———, B. L. Wessa, and J. L. Panero. 2002. Nuclear
rDNA evidence for major lineages of helenioid
Heliantheae (Compositae). Syst. Bot. 27: 161–198.
Barker, M. S., N. C. Kane, M. Matvienko, A. Kozik,
R. W. Michelmore, S. J. Knapp, and L. H.
Rieseberg. 2008. Multiple paleopolyploidizations
during the evolution of the Compositae reveal
parallel patterns of duplicate gene retention after
millions of years. Molec. Biol. Evol. 25: 2445–2455.
Barreda, V. D., L. Palazzesi, M. C. Telleria, L.
Katinas, J. V. Crisci, K. Bremer, M. G. Passalia,
R. Corsolini, R. R. Brizuela, and F. Bechis. 2010.
Eocene Patagonia fossils of the daisy family. Science
329: 1621.
Barringer, B. C. 2007. Polyploidy and self-fertilization
in flowering plants. Amer. J. Bot. 94: 1527–1533.
Bautista, H. P. 1987. Pectis L. (Compositae-Tageteae).
Espécies ocorrentes no Brasil. Arch. Jard. Bot. Rio
de Janeiro 28: 5–107.
Becerra, J. X. 2005. Timing the origin and expansion
of the Mexican tropical dry forest. Proc. Nalt. Acad.
Sci. (USA) 102: 10919–10923.
Besnard, G., A. M. Muasya, F. Russier, E. H. Roalson,
N. Salamin, and P.-A. Christin. 2009. Phylogenomics of C4 photosynthesis in sedges (Cyperaceae): multiple appearances and genetic convergence. Molec. Biol. Evol. 26: 1909–1919.
Bradley, C. E., and A. J. Haagen-Smit. 1949. Essential
oil of Pectis papposa. Econ. Bot. 3: 407–412.
Brennan, A. C., D. A. Tabah, S. A. Harris, and S. J.
Hiscock. 2011. Sporophytic self-incompatibility in
Senecio squalidus (Asteraceae): S allele dominance
interactions and modifiers of cross-compatibility
and selfing rates. Heredity 106: 113–123.
Britton, N. L., and A. Brown. 1913. An Illustrated
Flora of the Northern United States, Ed. 2. Vol 3. C.
Scribner’s Sons, New York.
———, and C. F. Millspaugh. 1920. The Bahama
Flora, pp. 456–457. Authors, New York.
Brown, N. J., K. Parsley, and J. M. Hibberd. 2005. The
future of C4 research - maize, Flaveria or Cleome?
Trends Pl. Sci. 10: 215–221.
Bye, R. 1996. Medicinal plants of the Sierra Madre:
comparative study of Tarahumara and Mexican
market plants. Econ. Bot. 40: 103–124.
Cabrera, A. L. 1978. Compositae (Parte X). In A. L.
Cabrera [ed.], Flora de la Provincia de Jujuy,
Republica Argentina. Coleccion Cientifica del INTA,
Buenos Aires.
Carr, G. D. 1988. Chromosome evolution and
speciation in Hawaiian flowering plants. In T. F.
Stuessy and M. Ono [eds.], Evolution and Speciation
of Island Plants. Cambridge University Press, Cambridge.
———, R. M. King, A. M. Powell, and H. Robinson.
1999. Chromosome numbers in Compositae.
XVIII. Amer. J. Bot 86: 1003–1013.
Cassini, H. 1819. Sixième mémoire sur la famille des
Synanthérées, contenant les caractères des tribus. J.
Physique Chimie Hist. Nat. 88: 150–163, 189–204.
Cerling, T. E. 1999. Paleorecords of C4 plants and
ecosystems. In R. F. Sage and R. K. Monson [eds.],
C4 plant biology, 445–469, Academic Press, San
Diego, California.
Christin, P.-A., C. P. Osborne, R. F. Sage, M. Arakaki,
and E. J. Edwards. 2011. C4 eudicots are not
younger than C4 monocots. J. Exp. Bot. 62:
3171–3181.
29
30
LUNDELLIA
———, T. L. Sage, E. J. Edwards, M. R. Ogburn, R.
Khoshravesh, and R. F. Sage. 2010. Complex
evolutionary transitions and the significance of C3–
C4 intermediate forms of photosynthesis in Molluginaceae. Evol. 65: 643–660.
———, G. Besnard, E. Samaritani, M. R. Duvall,
T. R. Hodkinson, V. Savolainen, and N. Salamin.
2008. Oligocene CO2 decline promoted C4 photosynthesis in grasses. Current Biol. 18: 37–43.
Cunningham, C. W. 1997. Can three incongruence
tests predict when data should be combined?
Molec. Biol. Evol. 14: 733–740.
da Silva, Milton Helie L., Eloisa Helena A. Andrade,
and José Guilherme S. Maia. 2005. The essential oil
of Pectis elongata Kunth occurring in north Brazil.
Flav. Frag. J. 20: 462–464.
Darlu, P., and G. Lecointre. 2002. When does the
incongruence length difference test fail? Molec.
Biol. Evol. 19: 432–437.
de Candolle, A. P. 1836. Prodromus systematis naturis
regni vegetabilis, sive enumeratio contracta ordinum
generum, specierumque plantarum. Treuttel &
Würtz, Paris.
Dillon, M., and B. L. Turner. 1982. Chromosome
numbers of some Peruvian Compositae. Rhodora
84: 131–137.
Downie, S. R., D. S. Katz-Downie, and M. F. Watson.
2000. A phylogeny of the flowering plant family
Apiaceae based on chloroplast DNA rpl16 and
rpoC1 intron sequences: towards a suprageneric
classification of subfamily Apioideae. Amer. J. Bot.
87: 273–292.
Downum, K. R., D. J. Keil, and E. Rodriguez. 1985.
Distribution of acetylenic thiophenes in the Pectidnae. Bioch. Syst. Ecol. 13: 109–113.
———, and E. Rodriguez. 1986. Toxicological action
and ecological importance of plant photosensitizers. J. Chem. Ecol. 12: 823–834.
———, S. Villegas, E. Rodriguez, and D. J. Keil.
1989. Plant photosensitizers: A survey of their
occurrence in arid and semiarid plants from North
America. J. Chem. Ecol. 15: 345–355.
Drummond, A. J., and A. Rambaut. 2007. BEAST:
Bayesian evolutionary analysis by sampling trees.
BMC Evol. Biol. 7: 214.
Elias, S. A., T. R. Van Devender, and R. de Baca. 1995.
Insect fossil evidence of late glacial and Holocene
environments in the Bolson De Mapimi, Chihuahuan Desert, Mexico: comparisons with the Paleobotanical record. Palaios 10: 454–464.
Engelmann, S., O. E. Blasing, U. Gowik, P. Svensson,
and P. Westhoff. 2003. Molecular evolution of C4
phosphoenolpyruvate carboxylase in the genus
Flaveria - a gradual increase from C3 to C4
characteristics. Planta 217: 717–725.
Felsenstein, J. 1988. Phylogenies from molecular
sequences: Inference and reliability. Ann. Rev.
Genet. 22: 521–565.
DECEMBER, 2016
Fernald, M. L. 1897. A systematic study of the United
States and Mexican species of Pectis. Proc. Amer.
Acad. Arts. Sci. 33: 57–86.
Gardner, G. 1846. Flora of Brazil. London J. Bot. 5:
239–242.
Gowik, U., and P. Westhoff. 2011. The path from C3
to C4 photosynthesis. Pl. Physiol. 155: 56–63.
Gray, A. 1849. Plantae Fendlerianae Novi-Mexicanae.
Mem. Amer. Acad. Arts. 4: 1–116.
———. 1852. Plantae Wrightianae Texano-Neo-Mexicanae. I. Smithsonian Contr. Knowledge 3: 1–146.
———. 1884. Contributions to North American
botany. Proc. Amer. Acad. Arts Sci. 19: 1–96.
———. 1888. Synoptical Flora of North America. The
Gamopetalae. Compositae. Smithsonian Miscellaneous Collections 591.
GSA. 2009. Geologic Timescale. The Geological Society
of America. Accessed March, 2012. http://www.
geosociety.org/science/timescale/.
Hansen, D. R., G. S. Spicer, and R. Patterson. 2009.
Phylogenetic relationships between and within
Phacelia sections Whitlavia and Gymnobythis (Boraginaceae). Syst. Biol. 34: 737–746.
Harpke, D., and A. Peterson. 2008. 5.8S motifs for the
identification of pseudogenic ITS regions. Botany
86: 300–305.
Hillis, D. M., and J. J. Bull. 1993. An empirical test of
bootstrapping as a method for assessing confidence
in phylogenetic analysis. Syst. Biol. 42: 182–192.
Hind, D. J. N. 2002. A new species of Porophyllum.
(Compositae: Heliantheae) from Bahia, Brazil. Kew
Bull. 57: 705–709.
Hiscock, S. J. 2000. Self-incompatibility in Senecio
squalidus L (Asteraceae). Ann. Bot. 85: 181–190.
Huelsenbeck, J. P., and F. Ronquist. 2001. MRBAYES:
Bayesian inference of phylogeny. Bioinformatics 17:
754–755.
Jansen, R. K., and J. D. Palmer. 1987. A chloroplast
DNA inversion marks an ancient evolutionary split
in the sunflower family (Asteraceae). Proc. Natl.
Acad. Sci. USA 84: 5818–5822.
Johnson, R. R. 1969. Monograph of the plant genus
Porophyllum (Compositae: Helenieae). Kansas
Univ. Sci. Bull. XL VIII: 225–267.
Jørgensen, P. M., and S. León-Yánez. 1999. Catalogue
of the Vascular Plants of Ecuador. In P. M.
Jørgensen and S. León-Yánez [eds.], Monographs
in Systematic Botany from the Missouri Botanical
Garden Missouri Botanical Garden Press, St. Louis.
Jung, M.-J., C.-W. Hsien, Y.-C. Kao, and C.-L. Yeh.
2011. Pectis L. (Asteraceae), a newly recorded genus
to the Flora of Taiwan. Taiwania 56: 173–176.
Kadereit, G., T. Borsch, K. Weising, and H. Freitag.
2003. Phylogeny of Amaranthaceae and Chenopodiaceae and the evolution of C4 photosynthesis.
Internatl. J. Pl. Sci. 164: 959–986.
Keil, D. J. 1975. Revision of Pectis sect. Heteropectis.
(Compositae: Tageteae). Madroño 23: 181–191.
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
———. 1977a. A revision of Pectis section Pectothrix
(Compositae: Tageteae). Rhodora 79: 32–78.
———. 1977b. Chromosome studies in North and
Central American species of Pectis L. (Compositae:
Tageteae). Rhodora 79: 79–93.
———. 1978. Revision of Pectis section Pectidium
(Compositae Tageteae). Rhodora 80: 135–146.
———. 1984. New species of Pectis (Asteraceae) from
the West-Indies, Mexico, and South-America.
Brittonia 36: 74–80.
———. 1996. Pectis. pp. 22–43 in The Comps of
Mexico: A systematic account of the Family
Asteraceae. 6: Tageteae and Anthemideae. Phytologia Mem. 10: 1–93.
———. 2002. Two new species of Pectis (Asteraceae:
Tageteae) from South America. Novon 12:
471–473.
———. 2006. Pectis. In: Flora of North America
Editorial Committee, eds. 1993+ Flora of North
America North of Mexico. 28+ vols. New York and
Oxford. Vol. 21, pp. 222–230.
———, and S. Stuessy. 1975. Chromosome counts of
Compositae from the United States, Mexico, and
Guatemala. Rhodora 77: 171–195.
———, and D. J. Pinkava. 1976. Chromosome counts
and taxonomic notes for Compositae from the
United States and Mexico. Amer. J. Bot. 63:
1393–1403.
———, and J. D. Morefield. 1989. Porophyllum
pygmaeum (Asteraceae) a disinctive new species
from southern Nevada. Syst. Bot. 14: 583–588.
———, M. A. Luckow, and D. J. Pinkava. 1988.
Chromosome-studies in Asteraceae from the United-States, Mexico, the West-Indies, and SouthAmerica. Amer. J. Bot. 75: 652–668.
Kellogg, E. A. 1999. Phylogenetic aspects of the
evolution of C4 photosynthesis. In R. F. Sage and
R. K. Monson [eds.], C4 Plant Biology, pp. 411–444,
Academic Press, San Diego, California.
Kim, K. J., K. S. Choi, and R. K. Jansen. 2005. Two
chloroplast DNA inversions originated simultaneously during the early evolution of the sunflower family
(Asteraceae). Molec. Biol. Evol. 22: 1783–1792.
Kimball, R. T., and D. J. Crawford. 2004. Phylogeny
of Coreopsideae (Asteraceae) using ITS sequences
suggests lability in reproductive characters. Molec.
Phylogenet. Evol. 33: 127–139.
Lagasca, M. 1816. Genera et species plantarum 28.
Matriti ex Typographia Regia.
Lessing, C. F. 1830. De synanthereis herbarii regni
Berolinensis. Dissertatio secunda. Nassauvieae.
Linnaea 5: 1–236.
Linnaeus, C. 1759. Systema naturae. Ed. 10. Tomus II:
Vegetabilia, Stockholm.
Liogier, A. H. 1962. Flora de Cuba, Tomo V. Editorial
Universitaria, Universidad de Puerto Rico, Rio
Piedras.
———. 1996. La flora de la Española. VIII. Universidad Central del Este, San Pedro de Macoris.
———. 2000. Flora of Puerto Rico and Adjacent Islands:
a Systematic Synopsis. Editorial de la Universidad de
Puerto Rico, Rio Piedras.
Loockerman, D. J., B. L. Turner, and R. K. Jansen.
2003. Phylogenetic relationships within the Tageteae (Asteraceae) based on nuclear ribosomal ITS
and chloroplast ndhF gene sequences. Syst. Bot. 28:
191–207.
Löve, Á. 1974. IOPB Chromosome number reports
XLV. Taxon 23: 619–624.
Maddison, D. R., and W. Maddison. 2005. MacClade
4: Analysis of phylogeny and character evolution.
Sinauer Associates, Inc., Sunderland, Massachusetts.
Marchese, J. A., F. Broetto, L. C. Ming, C. Ducatti,
R. A. Rodella, M. C. Ventrella, G. D. R. Gomes, and
L. de Franceschi. 2005. Carbon isotope composition
and leaf antomy as a tool to characterize the
photosynthetic mechanism of Artemisia annua L.
Brazilian J. Pl. Physiol. 17: 187–190.
Marshall, D. M., R. Muhaidat, N. J. Brown, Z. Liu, S.
Stanley, H. Griffiths, R. F. Sage, and J. M.
Hibberd. 2007. Cleome, a genus closely related to
Arabidopsis, contains species spanning a developmental progression from C3 to C4 photosynthesis.
Plant J. 51: 886–896.
McKown, A. D., and N. G. Dengler. 2007. Key
innovations in the evolution of Kranz anatomy and
C4 vein pattern in Flaveria (Asteraceae). Amer. J.
Bot. 94: 382–399.
———, J. M. Moncalvo, and N. G. Dengler. 2005.
Phylogeny of Flaveria (Asteraceae) and inference of
C4 photosynthesis evolution. Amer. J. Bot. 92:
1911–1928.
McNeill, J. 2006. International Code of Botanical
Nomenclature. Seventeenth International Botanical
Congress, Vienna, Austria, 146.
McVaugh, R. 1984. Pectis. In W. R. Anderson [ed.],
Flora Novo-Galiciana, 760–771, University of
Michigan Press, Ann Arbor.
Molero, J., A. Rovira, J. Simón, R. Duré, and D.
Franco. 2002. IOPB chromosome data 18. Newsletter Int. Organ. Pl. Biosyst. (Pruhonice) 34: 22–24.
Monson, R. K. 2003. Gene duplication, neofunctionalization, and the evolution of C4 photosynthesis.
Internatl. J. Pl. Sci. 164: S43–S54.
Muhaidat, R., R. F. Sage, and N. G. Dengler. 2007.
Diversity of Kranz anatomy and biochemistry in C4
eudicots. Amer. J. Bot. 94: 362–381.
Ocampo, G., and J. T. Columbus. 2010. Molecular
phylogenetics of suborder Cactineae (Caryophyllales), including insignts into photosynthetic diversification and historical biogeography. Amer. J.
Bot. 97: 1827–1847.
Osborne, C. P. 2011. The Geologic History of C4
Plants. In A. S. Raghavendra and R. F. Sage [eds.],
Advances in Photosynthesis and Respiration,
339–357, Springer, Dordrecht.
31
32
LUNDELLIA
Panero, J. L. 2007. Compositae: Tribe Tageteae Cass
(1819). In J. W. Kadereit and C. Jeffrey [eds.],
Flowering Plants, Eudicots, Asterales, 420–431,
Springer-Verlag, Berlin.
———, and V. A. Funk. 2008. The value of sampling
anomalous taxa in phylogenetic studies: major
clades of the Asteraceae revealed. Molec. Phylogen.
Evol. 47: 757–782.
Petersen, B. J., and B. Fry. 1987. Stable isotopes in
ecosystem studies. Ann. Rev. Ecol. Syst. 18:
293–320.
Pinkava, D. J., and D. J. Keil. 1977. Chromosome
counts of Compositae from the United States and
Mexico. Amer. J. Bot. 64: 680–686.
Posada, D., and K. A. Crandall. 1998. Modeltest:
testing the model of DNA substitution. Bioinformatics 14: 817–818.
Powell, A. M., and B. L. Turner. 1963. Chromosome
numbers in the Compositae. VII. Additional species
from the southwestern United States and Mexico.
Madroño 17: 128–140.
———, and S. Sikes. 1970. Chromosome numbers of
some Chihuahuan Desert Compositae. S. W.
Naturalist 15: 175–186.
Ralston, B., G. Nesom, and B. L. Turner. 1989.
Documented plant chromosome numbers 1989:1.
Chromosome numbers in Mexican Asteraceae with
special reference to the Tribe Tageteae. Sida 13:
359–368.
Rambaut, A. 2008. FigTree version 1.3.1. Distributed
by the author. http://tree.bio.ed.ac.uk/software/
figtree. Accessed March 2012.
———, and A. J. Drummond. 2007. Tracer v1.5 20032009 MCMC Trace Analysis Package. http://beast.
bio.ed.ac.uk/Tracer.
Raven, P. H., and D. W. Kyhos. 1961. Chromosome
numbers in Compositae. II. Helenieae. Amer. J.
Bot. 48: 842–850.
Reveal, J. L., and R. Moran. 1977. Miscellaneous
chromosome counts of western American plants—
IV. Madroño 24: 227–235.
———, and R. Spellenberg. 1976. Miscellaneous
chromosome counts of Western American
plants—III. Rhodora 78: 37–72.
Robinson, H. 1981. A revision of the tribal and
subtribal limits of the Heliantheae (Asteraceae).
Smithsonian Contrib. Bot. 51: 1–102.
———, A. M. Powell, R. M. King, and J. F. Weedin.
1981. Chromosome Numbers in Compositae, XII:
Heliantheae. Smithsonian Institution Press, Washington, D. C.
Rydberg, P. A. 1916. (Carduales) Carduaceae. Tageteae, Anthemidae. N. Am. Fl. 34: 181–288.
Sage, R. F. 2003. The evolution of C4 photosynthesis.
New Phytol. 161: 341–370.
———, P.-A. Christin, and E. J. Edwards. 2011. The
C4 plant lineages of planet Earth. J. ExPt. Bot. 62:
3155–3169.
DECEMBER, 2016
———, T. L. Sage, and R. W. Kocacinar. 2012.
Photorespiration and the evolution of C4 photosynthesis. Ann. Rev. Pl. Biol. 63: 19–47.
———, T. L. Sage, R. W. Pearcy, and T. Borsch. 2007.
The taxonomic distribution of C4 photosynthesis in
Amaranthaceae sensu stricto. Amer. J. Bot. 94:
1992–2003.
Schöch, E. 1971. Mata und Aspartat als Hauptprodukte der 14CO2-Kurzzeit Fixierung nun auch bei
einer Composite. Z. Pflanzenphysiol. 64: 367–368.
———, and K. Kramer. 1971. Korrelation von
Merkmalen der C4-Photosynthese bei Vertretern
verschiedner Ordnungen der Angiospermen. Planta
101: 51–66.
Seemann, B. 1852-1857. The Botany of the Voyage of
H.M.S. Herald: Under the Command of Captain
Henry Kellett, R.N., C.B., During the Years 1845-51.
Lovell Reeve, London.
Shaw, J., E. B. Lickey, E. E. Schilling, and R. L. Small.
2007. Comparison of whole chloroplast genome
sequences to choose noncoding regions for phylogenetic studies in angiosperms: the tortoise and the
hare III. Amer. J. Bot. 94: 275–288.
Shimodaira, H. 2002. An approximately unbiasted test
of phylogenetic tree selection. Syst. Biol. 51:
492–508.
———, and M. Hasegawa. 2001. CONSEL: for
assession the confidence of phylogenetic tree
selection. Bioinformatics 17: 1246–1247.
Smith, B. N., and B. L. Turner. 1975. Distribution of
Kranz syndrome among Asteraceae. Amer. J. Bot.
62: 541–545.
Soares, C. C., T. M. Marques, G. G. Rigolin, E. Neis,
A. M. V. Friaça, A. S. Silva, G. S. Barreto, and L.
Lopes. 2009. Atividade analgésica do extrato da
Pectis jangadensis (S. Moore). Braz. J. Pharmacognosy 19(1A): 77–81.
Spaulding, W. G., E. B. Leopold, and T. R. van
Devender. 1983. Late Wisconsin paleoecology of
the American Southwest. In S. C. Porter [ed.], LateQuarternary Environments of the United States.
University of Minnesota Press, Minneapolis.
Stamatakis, A. 2006. RAxML-VI-HPC: maximum
likelihood-based phylogenetic analysis with thousands of taxa and mixed models. Bioinformatics 22:
2688–2690.
Strother, J. L. 1977. Tageteae—systematic review. In
V. H. Heywood, J. B. Harborne, and B. L. Turner
[eds.], The Biology and Chemistry of the Compositae,
769–783, Academic Press, New York.
———. 1983. More chromosome studies in Compositae. Amer. J. Bot. 70: 1217–1224.
———, and J. L. Panero. 2001. Chromosome
studies: Mexican Compositae. Amer. J. Bot. 88:
499–502.
Timme, R. E., J. V. Kuehl, J. L. Boore, and R. K.
Jansen. 2007. A comparative analysis of the Lactuca
and Helianthus (Asteraceae) plastid genomes:
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
identification of divergent regions and categorization of shared repeats. Amer. J. Bot. 94: 302–312.
Turner, B. L. 1996. Porophyllam. pp. 43–50 in The
Comps of Mexico: A systematic account of the
Family Asteraceae. 6: Tageteae and Anthemideae.
Phytologia Memoirs 10: 1–93.
———, and D. Flyr. 1966. Chromosome numbers in
the Compositae. X. North American species. Amer.
J. Bot. 53: 24–33.
———, J. Bacon, L. Urbatsch, and B. Simpson. 1979.
Chromosome numbers in South American Compositae. Amer. J. Bot. 66: 173–178.
———, J. H. Beaman, and H. F. L. Rock. 1961.
Chromosome numbers in the Compositae. V.
Mexican and Guatemalan species. Rhodora 63:
121–129.
Van Devender, T. R. 2000. The deep history of the
Sonoran Desert. In S. J. Phillips and P. W. Cormus
[eds.], A Natural History of the Sonoran Desert,
61–69, Arizona-Sonoran Desert Museum Press,
Tucson.
Vogan, Pt. J., M. W. Frohlich, and R. F. Sage. 2007.
The functional significance of C3–C4 intermediate
traits in Heliotropium L. (Boraginaceae): gas
exhange perspectives. Plant. Cell Environ. 30:
1337–1345.
Wagner, W. L., D. R. Herbst, and S. H. Sohmer. 1990.
Manual of the Flowering Plants of Hawai’i (Bishop
Museum Special Publication). University of Hawai’i
Press, Bishop Museum Press, Honolulu.
Werle, E., C. Schneider, M. Renner, M. Völker, and
W. Fiehn. 1994. Convenient single-step, one tube
purification of PCR products for direct sequencing.
Nucl. Acids Res. 20: 4354–4355.
Westhoff, P., and U. Gowik. 2004. Evolution of C4
phosphoenolpyrovate carboxylase. Genes and proteins: a case study with the genus Flaveria. Ann.
Bot. 93: 13–23.
White, T. J., S. L. Bruns, and J. Taylor. 1990.
Amplification and direct sequencing of fungal
ribosomal RNA genes for phylogenetics. In M.
Innis, D. Gelfand, J. Sninsky, and T. White [eds.],
PCR Protocols: a Guide to Methods and Application,
315–322, Academic Press, San Diego.
Wiggins, I. L., and D. M. Porter. 1971. Flora of the
Galápagos Islands. Stanford University Press, Stanford, California.
Wilcox, T. P., D. J. Zwickl, T. A. Heath, and D. M.
Hillis. 2002. Phylogenetic relationships of the dwarf
boas and a comparison of Bayesian and bootstrap
measures of phylogenetic support. Molec. Phylogenet. Evol. 25: 361–371.
Wilgenbusch, J. C., D. L. Warren, and D. L. Swofford.
2004. AWTY: A system for graphical exploration of
MCMC convergence in Bayesian phylogenetic inference., http://ceb.csit.fsu.edu/awty.
Zhao, Z., and B. L. Turner. 1993. Documented
chromosome numbers 1993: 3. Miscellaneous
U.S.A. and Mexican species, mostly Asteraceae.
Sida 15: 649–653.
APPENDICES
APPENDIX 1. List of taxa sampled in the folowing order: taxon, i.d. number (when more than one accession per
species): voucher information (herbarium), GenBank accession numbers for ITS, matK, 3’ ndhF, rpl16 intron, trnLrpl32, 3’ trnV-ndhC, 5’ trnY-rpoB. An asterisk denotes accessions that did not amplify for a particular locus.
Herbarium acronyms follow Index Herbariorum.
Chrysactinia mexicana A. Gray, Coahuilla, Mexico, E. L. Bridges 13067 (TEX), KJ524912, KJ525212,
KJ525071, KJ557938, KJ558064, KJ525508, KJ525358. Nicolletia edwardsii A. Gray, Coahuilla, Mexico, D. R.
Hansen 65 (TEX), KJ524913, KJ525213, KJ525072, KJ557939, KJ558065, KJ525509, KJ525359. Pectis amplifolia D.J.
Keil, Oaxaca, Mexico, M. Elorsa C. 5010 (TEX), KJ524915, KJ525215, KJ525074, KJ557941, KJ558067, KJ525511,
KJ525361. Pt. angustifolia var. angustifolia Torr., No.1: Chihuahua, Mexico, D. R. Hansen 80 (TEX), KJ524916,
KJ525216, KJ525075, KJ557942, KJ558068, KJ525512, KJ525362. No. 2: Texas, U.S.A., B.L. Turner 22409 (TEX),
KJ524917, KJ525217, KJ525076, KJ557943, KJ558069, KJ525513, KJ525363. Pt. angustifolia var. fastigiata (A. Gray)
D.J. Keil, No. 1: Texas, U.S.A., D. R. Hansen 148 (TEX), KJ525060, KJ525351, KJ525204, KJ558055, KJ558212,
KJ525641, KJ525499. No. 2: Texas, U.S.A., W. R. Carr 15797 (TEX), KJ524918, KJ525218, KJ525077, KJ557944,
KJ558070, KJ525514, KJ525364. Pt. angustifolia var. tenella (DC.) D.J. Keil, No. 1: Mexico, D. R. Hansen 63 (TEX),
*, KJ525219, KJ525078, KJ557945, KJ558071, KJ525515, KJ525365. No. 2: Coahuila, Mexico, D. R. Hansen 69
(TEX), KJ524919, KJ525220, KJ525079, KJ557946, KJ558072, KJ525516, KJ525366. Pt. barberi Greenm.,
Chihuahua, Mexico, J. Spencer 1454 (TEX), KJ524920, KJ525221, KJ525080, KJ557947, KJ558073, KJ525517,
KJ525367. Pt. berlandieri DC., Tamaulipas, Mexico, M. C. Johnston 5579 (TEX), KJ524921, KJ525222, KJ525081,
KJ557948, KJ558074, KJ525518, KJ525368. Pt. bonplandiana Kunth, Belize City, Belize, R. D.Worthington 21255
(TEX), KJ524922, KJ525223, KJ525082, KJ557949, KJ558075, KJ525519, KJ525369. Pt. brevipedunculata Sch. BiPt.,
No. 1: Bahia, Brazil, V. C. Souza 5.391 (LL), KJ524923, KJ525224, KJ525083, *, KJ558076, KJ525520, KJ525370. No.
33
34
LUNDELLIA
DECEMBER, 2016
2: Minas Gerais, Brazil, R. M. Harley H 49978 (MO), KJ525030, KJ525323, KJ525178, KJ558029, KJ558182,
KJ525614, KJ525471. Pt. canescens Kunth, No. 1: Nariño, Colombia, B. R. Ramirez. Pt. s.n. (MO), KJ525029,
KJ525322, KJ525177, *, KJ558181, KJ525613, KJ525470. No. 2: Guerrero, Mexico, A. Cronquist 10842 (TEX),
KJ524924, KJ525225, KJ525084, KJ557950, KJ558077, KJ525521, KJ525371. No. 3: Sinaloa, Mexico, M. Ruiz G.
2006-459 (TEX), KJ524966, KJ525262, KJ525121, KJ557978, KJ558120, KJ525556, KJ525411. Pt. capillipes (Benth.)
Hemsl., El Salvador, J. M. Tucker 456 (LL), KJ524925, *, KJ525085, *, KJ558078, *, KJ525372. Pt. carthusianorum
Less., Dominican Republic, Dr. A. & P. Liogier (NYBG), KJ524926, *, KJ525086, *, KJ558079, * KJ525373. Pt.
ciliaris L., No. 1: San Cristobal, Dominican Republic, T. Classe 4401 (TEX), KJ524983, *, *, KJ557992, KJ558137,
KJ525571, *. No. 2: Monte Plata, Dominican Republic, D. R. Hansen 98 (TEX), KJ524927, KJ525226, KJ525087,
KJ557951, KJ558080, KJ525522, KJ525374. cf. ciliaris L., Guyas, Ecuador, E. Asplund 5620 (TEX), KJ524928,
KJ525227, KJ525088, *, KJ558081, KJ525523, KJ525375. Pt. coulteri Harv. & A. Gray, No. 1: Sonora, Mexico, A.
Sanders 13193 (TEX), KJ524929, KJ525228, *, KJ557952, KJ558082, KJ525524, KJ525376. No. 2: Sonora, Mexico,
A.L. Reina G. 2007-254 (TEX), KJ524931, KJ525230, KJ525090, *, KJ558084, KJ525526, KJ525378. No. 3: Sonora,
Mexico, D. R. Hansen 117 (TEX), KJ524930, KJ525229, KJ525089, KJ557953, KJ558083, KJ525525, KJ525377. Pt.
cubensis (A. Rich.) Griseb., Grand Cayman Island, N. Chevalier 149 (NYBG), KJ524932, KJ525231, KJ525091,
KJ557954, KJ558085, KJ525527, KJ525379. Pt. cylindrica (Fernald) Rydb., No. 1: Sonora, Mexico, A. L. Reina G.
2006-507 (TEX), KJ524933, KJ525232, KJ525092, KJ557955, KJ558086, KJ525528, KJ525380. No. 2: Sonora, Mexico,
T. R. Van Devender 2007-865 (TEX), KJ524934, KJ525233, KJ525093, KJ557956, KJ558087, KJ525529, KJ525381. Pt.
decemcarinata McVaugh, No. 1: Michoacan, Mexico, D. R. Hansen 139 (TEX), KJ525050, KJ525341, KJ525195,
KJ558045, KJ558202, KJ525631, KJ525490. No. 2: Michoacan, Mexico, Jose C. Soto Nuñez 3582 (MO), KJ525034,
KJ525326, KJ525180, KJ558031, KJ558186, KJ525616, KJ525474. No. 3: Michoacan, Mexico, M. Luckow 2937 (TEX),
KJ524935, KJ525234, KJ525094, KJ557957, KJ558088, KJ525530, KJ525382. Pt. depressa Fernald, No. 1: Guerrero,
Mexico, A. M. Powell & J. Edmondson 768 (TEX), KJ524936, KJ525235, KJ525095, KJ557958, KJ558089, KJ525531,
KJ525383. No. 2: Guerrero, Mexico, Y. Yahara 1353 (TEX), KJ525063, *, *, *, KJ558215, *, KJ525502. Pt. diffusa
Hook. & Arn., Michoacán, Mexico, D. R. Hansen 135 (TEX), KJ525048, KJ525339, KJ525193, KJ558043, KJ558200,
KJ525629, KJ525488. Pt. elongata var. elongata Kunth, Concepción, Paraguay, E. M. Sardini 38698 (MO), *, *, *,
KJ558185, *, *. Pt. elongata var. fasciculiflora (DC.) D.J. Keil, No. 1: Guerrero, Mexico, Fred R. Barrie 732 (TEX),
KJ524937, *, *, *, KJ558090, *, *. No. 2: Guerrero, Mexico, R. Torres C. 1809 (MO), KJ525033, KJ525325, *,
KJ558030, KJ558184, *, KJ525473. Pt. elongata var. floribunda (A. Rich.) D.J. Keil, No. 1: Monte Plata, Dominican
Republic, D. R. Hansen 100 (TEX), KJ524938, KJ525236, KJ525096, KJ557959, KJ558091, KJ525532, KJ525384. No.
2: Veracruz, Mexico, J. Dorantes 5076 (TEX), KJ524939, KJ525237, *, *, KJ558092, *, KJ525385. Pt. elongata var.
oerstediana (Rydb.) D.J. Keil, Guatemala, E. Contreras 10400 (TEX), KJ524940, KJ525238, KJ525097, *, KJ558093,
*, KJ525386. Pt. ericifolia D.J. Keil, Barbuda, Richard S. Cowan 1663 (NYBG), KJ524941, *, *, *, KJ558094, *, *. Pt.
exilis D.J. Keil, No. 1: Guerrero, Mexico, J. Calónico Soto 17612 (MEXU), KJ525058, KJ525349, KJ525202,
KJ558053, KJ558210, KJ525639, KJ525497. No. 2: Michoacán, Mexico, D. R. Hansen 138 (TEX), KJ525049,
KJ525340, KJ525194, KJ558044, KJ558201, KJ525630, KJ525489. Pt. exserta McVaugh, No. 1: Jalisco, Mexico, R.
McVaugh 26321 (MEXU), KJ525055, KJ525346, KJ525200, KJ558050, KJ558207, KJ525636, KJ525495. No. 2: Jalisco,
Mexico, A. C. Sanders 11177 (MO), KJ525032, KJ525324, KJ525179, *, KJ558183, KJ525615, KJ525472. Pt. filipes
var. filipes Harv. & A. Gray, Sonora, Mexico, A.L. Reina G. 2006-509 (TEX), KJ524943, KJ525240, KJ525099,
KJ557961, KJ558096, KJ525534, KJ525388. Pt. filipes var. subnuda Fernald, No. 1: Texas, U.S.A., Emily J. Lott 5257
(TEX), KJ524944, KJ525241, KJ525100, KJ557962, KJ558097, KJ525535, KJ525389. No. 2: New Mexico, U.S.A., R.
D. Worthington 27323 (TEX), KJ524945, KJ525242, KJ525101, KJ557963, KJ558098, KJ525536, KJ525390. No. 3:
Arizona, U.S.A., D. R. Hansen 85 (TEX), KJ524942, KJ525239, KJ525098, KJ557960, KJ558095, KJ525533, KJ525387.
Pt. glaucescens (Cass.) D.J. Keil, No. 1: Bahama Islands, D. S. Correll 49664 (NYBG), KJ524947, KJ525244,
KJ525103, KJ557965, KJ558100, KJ525538, KJ525392. No. 2: Florida, U.S.A., Ruben Pt. 8755 (TEX), KJ524948, *,
KJ525104, *, KJ558101, *, *. No. 3: Districto Nacional, Dominican Republic, D. R. Hansen 111 (TEX), KJ524946,
KJ525243, KJ525102, KJ557964, KJ558099, KJ525537, KJ525391. Pt. graveolens Klatt, Colombia, J. E. Ramos 459
(MO), KJ525028, KJ525321, KJ525176, KJ558028, KJ558180, KJ525612, KJ525469. Pt. haenkeana (DC.) Sch. Bip,
No. 1: Guerrero, Mexico, M. Luckow 3548 (TEX), KJ524949, KJ525245, KJ525105, KJ557966, KJ558102, KJ525539,
KJ525393. No. 2: Oaxaca, Mexico, J. Calónico Soto 24000 (MEXU), KJ525056, KJ525347, *, KJ558051, KJ558208,
KJ525637, *. Pt. holochaeta var. cana D.J. Keil, No. 1: Michoacan, Mexico, J. C. Soto Núñez 4257 (MEXU),
KJ525054, KJ525345, KJ525199, KJ558049, KJ558206, KJ525635, KJ525494. No. 2: Michoacan, Mexico, M.Luckow
with F.Barrie 3493 (LL), KJ524950, KJ525246, KJ525106, KJ557967, KJ558103, KJ525540, KJ525394. Pt. holochaeta
var. holochaeta (S.F.Blake) D.J. Keil, Guerrero, Mexico, J. Calónico Soto 11952 (MEXU), KJ525057, KJ525348,
KJ525201, KJ558052, KJ558209, KJ525638, KJ525496. Pt. humifusa Sw., No. 1: Puerto Rico, U.S.A., D. R. Hansen 95
(TEX), KJ524951, KJ525247, KJ525107, KJ557968, KJ558104, KJ525541, KJ525395. No. 2: Puerto Rico, U.S.A., D. R.
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
Hansen 96 (TEX), KJ524952, KJ525248, KJ525108, *, KJ558105, KJ525542, KJ525396. Pt. imberbis A. Gray, No. 1:
Arizona, U.S.A., E. Lehto L20487 (LL), KJ524953, KJ525249, KJ525109, KJ557969, KJ558106, KJ525543, KJ525397.
No. 2: Arizona, U.S.A., J. E. Bowers 3702 (ARIZ), KJ524955, KJ525251, KJ525111, *, KJ558108, KJ525545, KJ525399.
No. 3: Arizona, U.S.A., M. Fishbein #1508 (ARIZ), KJ524954, KJ525250, KJ525110, KJ557970, KJ558107, KJ525544,
KJ525398. Pt. incisifolia I.M. Johnst., No. 1: Coahuila, Mexico, J. Henrickson 6991 (LL), KJ525066, KJ525355,
KJ525209, KJ558060, KJ558217, KJ525646, KJ525505. No. 2: Chihuahua, Mexico, D. R. Hansen 72 (TEX), KJ524956,
KJ525252, KJ525112, KJ557971, KJ558109, KJ525546, KJ525400. Pt. latisquama Sch. BiPt. ex Greenm., Puebla,
Mexico, Robert Merrill King 3557 (LL), KJ524957, KJ525253, KJ525113, KJ557972, KJ558110, KJ525547, KJ525401.
Pt. leavenworthii Standl., No. 1: Michoacán, Mexico, D. R. Hansen 132 (TEX), KJ525047, KJ525338, KJ525192,
KJ558042, KJ558199, KJ525628, KJ525487. No. 2: Michoacán, Mexico, B.L. Turner P-70 (TEX), KJ524958,
KJ525254, KJ525114, *, KJ558111, KJ525548, KJ525402. Pt. leonis Rydb., , Cuba, George R. Proctor 3138 (NYBG),
KJ524959, KJ525255, *, *, KJ558112, KJ525549, KJ525403. Pt. liebmannii Sch. BiPt. ex Hemsl., No. 1: Oaxaca,
Mexico, Misael Elorsa C. 778 (MEXU ), KJ525059, KJ525350, KJ525203, KJ558054, KJ558211, KJ525640, KJ525498.
No. 2: Oaxaca, Mexico, Hinton et al. 26470 (TEX), KJ524960, KJ525256, KJ525115, *, KJ558113, KJ525550,
KJ525404. Pt. linearifolia Urb., Florida, U.S.A., J. D. Ray, Jr. 10160 (TEX), KJ524961, KJ525257, KJ525116,
KJ557973, KJ558114, KJ525551, KJ525405. Pt. linearis La Llave, Jamaica, M.R. Crosby 141 (LL), KJ524962,
KJ525258, KJ525117, KJ557974, KJ558115, KJ525552, KJ525406. Pt. linifolia var. hirtella S.F. Blake, No. 1:
Michoacán, Mexico, D. R. Hansen 123 (TEX), KJ525045, KJ525337, KJ525191, KJ558040, KJ558196, KJ525626,
KJ525485. No. 2: Michoacán, Mexico, D. R. Hansen 143 (TEX), KJ525052, KJ525343, KJ525197, KJ558047,
KJ558204, KJ525633, KJ525492. Pt. linifolia var. linifolia L., No. 1: Amazonas, Peru, H. van der Werff 15886 (MO),
KJ525027, KJ525320, KJ525175, KJ558027, KJ558179, KJ525611, KJ525468. No. 2: Azua, Dominican Republic, D. R.
Hansen 107 (TEX), KJ524963, KJ525259, KJ525118, KJ557975, KJ558116, KJ525553, KJ525407. No. 3: Arizona,
U.S.A., E. Lehto L20273 (LL), KJ524964, KJ525260, KJ525119, KJ557976, KJ558117, KJ525554, KJ525408. Pt.
longipes A. Gray, No. 1: Arizona, U.S.A., S. Sundberg 2114 (TEX), KJ524965, KJ525261, KJ525120, KJ557977,
KJ558118, KJ525555, KJ525409. No. 2: Sonora, Mexico, T. R. Van Devender 2008-249 (TEX), KJ525044, KJ525336,
KJ525190, KJ558039, KJ558195, KJ525625, KJ525484. Pt. luckoviae D.J. Keil, No. 1: Michoacán, Mexico, D. R.
Hansen 140 (TEX), KJ525051, KJ525342, KJ525196, KJ558046, KJ558203, KJ525632, KJ525491. No. 2: Michoacán,
Mexico, D. R. Hansen 145 (TEX), KJ525053, KJ525344, KJ525198, KJ558048, KJ558205, KJ525634, KJ525493. Pt.
multiceps Urb., Dominican Republic, A. H. Liogier 12330 (NYBG), KJ524967, KJ525263, KJ525122, KJ557979,
KJ558121, KJ525557, KJ525412. Pt. multiflosculosa (DC.) Sch. BiPt., , Costa Rica, W. Haber 9243 (LL), KJ524968
(ITS clone 1), KJ524969 (ITS clone 2), KJ525264, KJ525123, KJ557980, KJ558123, KJ525558, KJ525414. Pt.
multiseta var. ambigua (Fernald) D.J. Keil, Baja Calif. Sur, Mexico, S. W. Sikes 274 (TEX), KJ524970, KJ525265,
KJ525124, KJ557981, KJ558124, KJ525559, KJ525415. Pt. multiseta var. multiseta Benth., No. 1: Baja Calif Sur,
Mexico, Melissa Luckow 2827 (TEX), KJ524971, KJ525266, KJ525125, KJ557982, KJ558125, KJ525560, KJ525416.
No. 2: Baja Calif Sur, Mexico, D. R. Hansen 149 (TEX), KJ525061, KJ525352, KJ525205, KJ558056, KJ558213,
KJ525642, KJ525500. Pt. odorata Griseb., No. 1: Beni, Bolivia, S.G. Beck 12815 (LPB), KJ524972, KJ525267,
KJ525126, KJ557983, KJ558126, KJ525561, KJ525417. No. 2: Central, Paraguay, F. Mereles 3971 (MO), KJ525026,
KJ525319, KJ525174, KJ558026, KJ558178, KJ525610, KJ525466. Pt. oligocephala var. oligocephala Sch. BiPt., No.
1: Goiás, Brazil, H. S. Irwin (NYBG), KJ524973, KJ525268, KJ525127, KJ557984, KJ558127, KJ525562, KJ525418.
No. 2: Goiás, Brazil, W. R. Anderson 6859 (NYBG), KJ524974, KJ525269, KJ525128, *, KJ558128, KJ525563,
KJ525419. Pt. papposa var. grandis D.J. Keil, No. 1: Chihuahua, Mexico, D. R. Hansen 78 (TEX), KJ524976,
KJ525271, KJ525130, KJ557986, KJ558130, KJ525564, KJ525421. No. 2: Texas, U.S.A., D. R. Hansen 62 (TEX),
KJ524975, KJ525270, KJ525129, *, KJ558129, KX815121, KJ525420. Pt. papposa var. papposa Harv. & A. Gray, No.
1: Arizona, U.S.A., D. R. Hansen 83 (TEX), KJ524977, KJ525272, KJ525131, KJ557986, KJ558131, KJ525565,
KJ525422. No. 2: California, U.S.A., B. Pitzer 4021 (TEX), KJ525068, KJ525357, KJ525211, KJ558062, KJ558219,
KJ525648, KJ525507. Pt. portoricensis Urb., , Puerto Rico, T. A. Zanoni (NYBG), KJ524978, KJ525273, KJ525132,
KJ557987, KJ558132, KJ525566, KJ525423. Pt. pringlei Fernald, No. 1: Chihuahua, Mexico, D. R. Hansen 74 (TEX),
KJ524979, KJ525274, KJ525133, KJ557988, KJ558133, KJ525567, KJ525424. No. 2: Chihuahua, Mexico, A. Cronquist
10759, (TEX), KJ525067, KJ525356, KJ525210, KJ558061, KJ558218, KJ525647, KJ525506. Pt. propetes Greenm.,
Zacatecas, Mexico, D. E. Breedlove 61549 (TEX), KJ524980, KJ525275, KJ525134, KJ557989, KJ558134, KJ525568,
KJ525425. Pt. prostrata Cav., No. 1: Arizona, U.S.A., D. R. Hansen 86 (TEX), KJ524981, KJ525276, KJ525135,
KJ557990, KJ558135, KJ525569, KJ525426. No. 2: Sinaloa, Mexico, D. R. Hansen 120 (TEX), KJ524984, KJ525278,
KJ525137, KJ557993, KJ558138, KJ525572, KJ525428. No. 3: Texas, U.S.A., W. R. Carr 19134 (TEX), KJ524982,
KJ525277, KJ525136, KJ557991, KJ558136, KJ525570, KJ525427. No. 4: Managua, Nicaragua, M. Guzman 425
(MO), KJ525038, KJ525330, KJ525184, KJ558033, KJ558190, KJ525619, KJ525478. Pt. purpurea var. sonorae D.J.
Keil, Sonora, Mexico, T. R. Van Devender 92-1061 (TEX), KJ524985, KJ525279, KJ525138, KJ557994, KJ558139,
35
36
LUNDELLIA
DECEMBER, 2016
KJ525573, KJ525429. Pt. pusilla Urb., Haiti, E. L. Ekman 8343 (LL), KJ524986, KJ525280, KJ525139, KJ557995,
KJ558140, KJ525574, KJ525430. Pt. repens Brandegee, No. 1: Queretaro, Mexico, J. Rzedowski (TEX), KJ524987,
KJ525281, KJ525140, KJ557996, KJ558141, KJ525575, KJ525431. No. 2: Guanajuato, Mexico, R. Galván 2578 (MO),
KJ525039, KJ525331, KJ525185, KJ558034, KJ558191, KJ525620, KJ525479. Pt. saturejoides (Mill.) Sch. BiPt., No.
1: Oaxaca, Mexico, A. Saynes V. 4246 (TEX), KJ524988, KJ525282, KJ525141, KJ557997, KJ558143, KJ525576,
KJ525433. No. 2: El Progreso, Guatemala, M. Garcia 671 (MO), KJ525037, KJ525329, KJ525183, KJ558032,
KJ558189, KJ525618, KJ525477. No. 3: Oaxaca, Mexico, M. Elorsa C. 7760 (TEX), KJ524914, KJ525214, KJ525073,
KJ557940, KJ558066, KJ525510, KJ525360. Pt. sessiliflora (Less.) Sch. BiPt., No. 1: Jujuy, Argentina, A. Krapovickas
46652, (TEX), KJ524989, KJ525283, KJ525142, KJ557998, *, KJ525577, KJ525434. No. 2: La Paz, Bolivia, St. G. Beck
7987 (LPB), KJ524990, KJ525284, KJ525143, KJ557999, KJ558144, KJ525578, KJ525435. Pt. sinaloensis Fernald, No.
1: Sinaloa, Mexico, A.L.Reina G. 2005-1606 (ARIZ), KJ524992, KJ525286, KJ525145, KJ558001, KJ558146,
KJ525580, KJ525437. No. 2: Sinaloa, Mexico, D. Flyr 135 (TEX), KJ524991, KJ525285, KJ525144, KJ558000,
KJ558145, KJ525579, KJ525436. Pt. stella Malme, Mato Grosso, Brazil, G. Hatschbach 62720 (MO), KJ525025,
KJ525318, *, *, KJ558177, *, *. Pt. stenophylla var. biaristata (Rydb.) D.J. Keil, Sonora, Mexico, S. Sikes 1788 (TEX),
KJ525064, *, KJ525207, KJ558058, *, KJ525644, KJ525503. Pt. stenophylla var. puberula (Greenm.) D.J. Keil,
Sinaloa, Mexico, A. T. Whittemore 83-035 (TEX), KJ525065, KJ525354, KJ525208, KJ558059, KJ558216, KJ525645,
KJ525504. Pt. stenophylla var. stenophylla A.Gray, Chihuahua, Mexico, W. A.Weber & R. Bye 8382 (TEX),
KJ524994, KJ525288, KJ525147, KJ558003, KJ558148, KJ525582, KJ525439. Pt. c.f. stenophylla A.Gray, Sonora,
Mexico, A. L.Reina G. 2007-1034 (TEX), KJ524993, KJ525287, KJ525146, KJ558002, KJ558147, KJ525581, KJ525438.
Pt. tenuicaulis Urb., No. 1: Dominican Republic, Bro. A. H. Liogier (NYBG), KJ524995, KJ525289, KJ525148, *,
KJ558149, KJ525583, KJ525440. No. 2: Boyaca, Colombia, John Olsen and Linda Escobar 590 (LL), KJ524996,
KJ525290, KJ525149, KJ558004, KJ558150, KJ525584, KJ525441. Pt. tenuifolia (DC.) Sch. BiPt., Galápagos Islands,
Ecuador, I. L. Wiggins & D. M. Porter 210 (NYBG), KJ524997, KJ525291, KJ525150, *, KJ558151, KJ525585,
KJ525442. Pt. uniaristata var. holostemma A. Gray, No. 1: Valle, Honduras, D. Keil 9509 (MO), KJ525036,
KJ525328, KJ525182, *, KJ558188, KJ525617, KJ525476. No. 2: Nueva Segovia, Nicauragua, W.D. Stevens 3069
(MO), KJ525035, KJ525327, KJ525181, *, KJ558187, KJ525617, KJ525475. Pt. uniaristata var. jangadensis (S.
Moore) D.J. Keil, Sinaloa, Mexico, T. R. Van Devender 2004-1488 (TEX), KJ524998, KJ525292, KJ525151, KJ558005,
KJ558152, KJ525586, KJ525443. Pt. uniaristata var. uniaristata DC., No. 1: Sonora, Mexico, A. L. Reina G. 20061311 (TEX), KJ524999, KJ525293, KJ525152, KJ558006, KJ558153, KJ525587, KJ525444. Pt. vandevenderi B.L.
Turner, Sonora, Mexico, A. L. Reina G. 2007-1030 (TEX), KJ525000, KJ525294, KJ525153, KJ558007, KJ558154,
KJ525588, KJ525445. Pt. vollmeri Wiggins, Baja Calif Sur, Mexico, T. L.Burgess 6134 (ARIZ), KJ525001, KJ525295,
KJ525154, KJ558008, KJ558155, KJ525589, KJ525446. Porophyllum amplexicaule Engelm. ex A. Gray, Nuevo Leon,
Mexico, Hinton 22702 (TEX), KJ525002, KJ525296, KJ525155, KJ558009, KJ558156, KJ525590, KJ525447. Pr.
angustissimum Gardner, Minas Gerais, Brazil, H. S. Irwin (LL), KJ525003, KJ525297, KJ525156, KJ558010,
KJ558157, KJ525591, KJ525448. Pr. calcicola B.L. Rob. & Greenm., Guerrero, Mexico, S.D. Koch 7984 (TEX),
KJ525004, KJ525298, KJ525157, KJ558011, KJ558158, KJ525592, KJ525449. Pr. coloratum var. coloratum (Kunth)
DC., Sonora, T. R. Van Devender 95-447 (TEX), KJ525005, KJ525299, KJ525158, KJ558012, KJ558159, KJ525593,
KJ525450. Pr. coloratum var. obtusifolium (DC.) McVaugh, Aguascalientes, Mexico, J. Rzedowski & R. McVaugh
868 (TEX), KJ525006, KJ525300, KJ525159, KJ558013, KJ558160, KJ525594, KJ525451. Pr. filiforme Rydb., Nuevo
Leon, Mexico, Hinton 20959 (TEX), KJ525007, KJ525302, *, *, *, *, KJ525453. Pr. gracile Benth, California, USA, L.
Gross 1276 (RSA), KJ525009, KJ525303, KJ525161, KJ558015, KJ558161, KJ525596, KJ525454. Pr. greggii A. Gray,
Texas, U.S.A., S. Sikes & J. Smith 531 (TEX), KJ525010, KJ525304, KJ525162, KJ558016, KJ558162, KJ525597,
KJ525455. Pr. lanceolatum DC., Corrientes, Argentina, A. Schinini (TEX), KJ525011, KJ525305, KJ525163,
KJ558017, KJ558163, KJ525598, KJ525456. Pr. leiocarpum (Urb.) Rydb, , Puerto Rico, A. H. Liogier (NYBG),
KJ525012, KJ525306, KJ525164, KJ558018, KJ558164, KJ525599, KJ525457. Pr. linaria (Cav.) DC., No. 1: Puebla,
Mexico, David Keil 15479 (TEX), KJ525013, KJ525307, KJ525165, KJ558019, KJ558165, KJ525600, KJ525458; No 2:
Oaxaca, Mexico, J. I. Calzada 20259 (TEX), KJ525014, KJ525308, KJ525166, KJ558020, KJ558166, KJ525601,
KJ525459. Pt. lindenii Sch. Bip, Jalisco, Mexico, J. L. Panero 2872 (TEX), KJ525015, KJ525309, KJ525167, KJ558021,
KJ558167, KJ525602, KJ525460. Pr. linifolium (Ard.) DC. Central, Paraguay, E. M. Zardini 36323 (MO), KJ525043,
KJ525335, KJ525189, KJ558038, KJ558194, KJ525624, KJ525483. Pr. macrocephalum DC., No. 1: Honduras, T. F.
Daniel 9591 (MO), KJ525040, KJ525332, KJ525186, KJ558035, KJ558192, KJ525621, KJ525480. No. 2: Tamaulipas,
Mexico, T. F. Patterson 7388 (TEX), KJ525016, KJ525310, KJ525168, KJ558022, KJ558168, KJ525603, KJ525461. No.
3: Chiapas, Mexico, A. Reyes-Garcia 5623 (TEX), KJ525041, KJ525333, KJ525187, KJ558036, *, KJ525622, KJ525481.
No. 4: Sonora, Mexico, A.L. Reina G 2006-1180 (TEX), KJ525021, KJ525315, KJ525172, KJ558024, KJ558173,
KJ525607, KJ525465. Pr. maritimum Brandegee, No. 1: Baja California Sur, Mexico, M. Luckow 2866 (TEX),
KJ525017, KJ525311, KJ525169, *, KJ558169, KJ525604, KJ525462. No. 2: Baja California Sur, Mexico, D. R. Hansen
NUMBER 19
HANSEN ET AL.: PECTIS AND POROPHYLLUM PHYLOGENY AND C4 PHOTOSYNTHESIS
150 (TEX), KJ525062, KJ525353, KJ525206, KJ558057, KJ558214, KJ525643, KJ525501. Pr. pausodynum B.L. Rob.
& Greenm., Sonora, Mexico, Richard S. Felger 85-1530 (TEX), KJ525018, KJ525312, *, *, KJ558170, *, *. Pr.
punctatum (Mill.) S.F. Blake, No. 1: Sinaloa, Mexico, J. L. Panero 6179 (TEX), KJ525020, KJ525314, KJ525171,
KJ558023, KJ558172, KJ525606, KJ525464. No. 2: Belize, R. D. Worthington 23852 (TEX), KJ525019, KJ525313,
KJ525170, *, KJ558171, KJ525605, KJ525463. Pr. ruderale (Jacq.) Cass., Ecuador, R. M. King 10060 (MO),
KJ525042, KJ525334, KJ525188, KJ558037, KJ558193, KJ525623, KJ525482. Pr. cf. ruderale (Cass.) A. Gray ex B.L.
Rob., Goiás, Brazil, H. S. Irwin (TEX), KJ525007, KJ525301, KJ525160, KJ558014, *, KJ525595, KJ525452. Pr.
scoparium A. Gray, Chihuahua, Mexico, D. R. Hansen 79 (TEX), KJ525022, KJ525316, *, *, KJ558174, KJ525608, *.
Pr. viridiflorum (Kunth) DC., Guerrero, Mexico, J. L. Panero 6187 (TEX), KJ525023, KJ525317, KJ525173,
KJ558025, KJ558175, KJ525609, KJ525466. Pr. zimapanum B.L. Turner, Zacatecas, Mexico, L. Woodruff 397 (TEX),
KJ525024, *, *, *, KJ558176, *, *. Tagetes erecta Fernald, Michoacán, Mexico, D. R. Hansen 126 (TEX), KJ525046, *,
*, KJ558041, KJ558197, KJ525627, *.
APPENDIX 2. List of taxa used for molecular dating, in the following order: taxon, available voucher
information (herbarium), GenBank accession numbers for matK, ndhF. Herbarium acronyms follow Index
Herbariorum. If the matK and ndhF sequences are from different collections, they are listed separately after the
species name. Sequences representing Barnadesia and Flaveria were taken from different species because matK and
ndhF were not available from the same species.
Arctotis hirsuta (Harv.) Pt. Beauv., J. Panero 2002-61, cultivated, seed source: Kirstenboch Botanical Garden,
South Africa (TEX), EU385224, EU385133. Artemisia tridentata Nutt., matK: AF456776; ndhF: A. Kornkven 11872
(OKL), AF153630. Barnadesia Mutis ex L. f. matK: B. spinosa L.f., Argentina, Panero and Crozier 8492 (TEX),
EU385327; ndhF: B. caryophyla (Vell.) S.F. Blake, L39394. Centaurea melitensis L., USA, J. Panero 2002-48, (TEX),
EU385332, EU385140. Chrysactinia mexicana A. Gray, Coahuilla, Mexico, E. L. Bridges 13067 (TEX), KJ525212,
KJ525071. Dicoma capensis Less., South Africa, Trinder-Smith 349 (US), EU385344, EU385152. Doniophyton
anomalum (D. Don) Kurtz, Argentina, Bonifacino 96, (US), EU385348, EU385156. Flaveria Juss., matK: F.
australasica Hook., AF456788; ndhF: F. ramosissima Klatt, Keil 15588 (TEX); AF405266. Gerera serrata (Thunb.)
Druce, South Africa, Koekemoer 2001 (US), EU385356, EU385164. Gochnatia hypoleuca (DC.) A. Gray, Mexico, J.
Panero MEX-1 (TEX), EU385357, EU385165. Helianthus annuus L. cultivar line HA383, ABD47127.1, ABD47204.
Inula britannica L., Santos and Francisco ACC55-98, cultivated at TEX, (ORT), AY215812, AF384737. Lactuca
sativa L. cultivar Salinas, ABD47214.1, ABD47291.1. Mutisia retrorsa Cav., Argentina, Bonifacino 148 (US),
EU385376, EU385185. Nicolletia edwardsii A. Gray, Coahuilla, Mexico, D. R. Hansen 65 (TEX), KJ525213,
KJ525072. Pectis angustifolia var. angustifolia Torr., Texas, U.S.A., B.L. Turner 22409 (TEX), KJ525217, KJ525076.
Pectis barberi Greenm., Chihuahua, Mexico, J. Spencer 1454 (TEX), KJ525221, KJ525080. Pectis coulteri Harv. & A.
Gray, Sonora, Mexico, D. R. Hansen 117 (TEX), KJ525229, KJ525089. Pectis cylindrica (Fernald) Rydb., Sonora,
Mexico, A.L. Reina G. 2006-507 (TEX), KJ525232, KJ525092. Pectis decemcarinata McVaugh, Michoacan, Mexico,
D. R. Hansen 139 (TEX), KJ525341, KJ525195. Pectis elongata var. floribunda (A. Rich.) D.J. Keil, Monte Plata,
Dominican Republic, D. R. Hansen 100 (TEX), KJ525236, KJ525096. Pectis filipes var. filipes Harv. & A. Gray,
Sonora, Mexico, A.L. Reina G. 2006-509 (TEX), KJ525240, KJ525099. Pectis filipes var. subnuda Fernald, New
Mexico, U.S.A., R. D. Worthington 27323 (TEX), KJ525242, KJ525101. Pectis humifusa Sw., Puerto Rico, U.S.A., D.
R. Hansen 95 (TEX), KJ525247, KJ525107. Pectis imberbis A. Gray, Arizona, U.S.A., M. Fishbein #1508 (ARIZ),
KJ525250, KJ525110. Pectis incisifolia I.M. Johnst., Chihuahua, Mexico, D. R. Hansen 72 (TEX), KJ525252,
KJ525112. Pectis linifolia L. Arizona, U.S.A., E. Lehto L20273 (LL), KJ525260, KJ525119. Pectis linifolia var. hirtella
S.F. Blake, Michoacán, Mexico, D. R. Hansen 143 (TEX), KJ525045, KJ525337. Pectis longipes A. Gray, Arizona,
U.S.A., Scott Sundberg 2114 (TEX), KJ525261, KJ525120. Pectis multiseta var. multiseta Benth., Baja Calif Sur,
Mexico, D. R. Hansen 149 (TEX), KJ525352, KJ525205. Pectis oligocephala var. oligocephala Sch. BiPt., Goiás,
Brazil, W. R. Anderson 6859 (NYBG), KJ525269, KJ525128. Pectis papposa var. grandis D.J. Keil, Texas, U.S.A., D.
R. Hansen 62 (TEX), KJ525270, KJ525129. Pectis papposa var. papposa Harv. & A. Gray, California, U.S.A., B.
Pitzer 4021 (TEX), KJ525357, KJ525211. Pectis tenuifolia (DC.) Sch. BiPt., Galápagos Islands, Ecuador, Ira L.
Wiggins & D. M. Porter 210 (NYBG), KJ525291, KJ525150. Pectis uniaristata var. uniaristata DC., No. 1: Sonora,
Mexico, A.L. Reina G. 2006-1311 (TEX), KJ525293, KJ525152. Pectis vandevenderi B.L. Turner, Sonora, Mexico, A.
L. Reina G. 2007-1030 (TEX), KJ525294, KJ525153. Perezia purpurata Wedd., Argentina, Simon 594 (US)
EU385385, EU385194. Porophyllum amplexicaule Engelm. ex A. Gray, Nuevo Leon, Mexico, Hinton 22702 (TEX),
KJ525296, KJ525155. Porophyllum angustissimum Gardner, Minas Gerais, Brazil, H. S. Irwin (LL), KJ525297,
KJ525156. Porophyllum coloratum var. coloratum (Kunth) DC., Sonora, Mexico, T. R. Van Devender 95-447
(TEX), KJ525299, KJ525158. Porophyllum gracile Benth, California, USA, L. Gross 1276 (RSA), KJ525303,
KJ525161. Porophyllum linaria (Cav.) DC., Puebla, Mexico, David Keil 15479 (TEX), KJ525307, KJ525165.
37
38
LUNDELLIA
DECEMBER, 2016
Porophyllum macrocephalum DC., Sonora, Mexico, A. L. Reina G 2006-1180 (TEX), KJ525315, KJ525172.
Porophyllum maritimum Brandegee, Baja California Sur, Mexico, D. R. Hansen 150 (TEX), KJ525353, KJ525206.
Sonchus oleraceus L., USA, J. Panero 2002-80, (TEX). EU385397, EU385206. Tagetes patula L., matK: Mexico:
Commercial source, Bayer s.n. (CANB), AF151515; ndhF: AB530942.