Navarretia

Navarretia is a genus of at least 44 species native to North America, with one species endemic to South America. Navarretia squarrosa is introduced in Australia in New Zealand. Ongoing research by Leigh Johnson and Dave Gowen has resulted the recognition of several new, “cryptic” species (e.g., Johnson et al. 2013; Johnson & Gowen 2017). There will doubtlessly be continued changes in the near future.

Grant (1959) recognized four taxonomic sections (sects. Aegochloa, Masonia, Mitracarpium, and Navarretia) based on combinations of fruit (dehiscence, locule number), bract shape (base width, texture), number of corolla veins, and number of stigma lobes, among other morphological traits. This classification was doubtless based on the work of Crampton (1954). Because many traits were not consistent among sections, various slight sectional rearrangements were later made (e.g., Day [1993]).

In addition, the generic circumscription of Navarretia has been controversial, particularly given that molecular evidence clearly places species formerly assigned to Gilia sect. Kelloggia (Day 1993) in a clade or grade sister to Navarretia sensu stricto (Johnson & Soltis 1995; Johnson et al. 1996; Spencer & Porter 1997; Johnson et al. 2010). While Grant & Day (1999) erroneously argued for these species to be included in Allophyllum, given the close relationship of Allophyllum to Navarretia, the morphological similarities in pollen, trichomes, and seeds of members of Gilia sect. Kelloggia with Allophyllum make sense. In recognizing members of Gilia sect. Kelloggia within Navarretia, Porter & Johnson (2000) note that while they:

“are distinguished from other Navarretia on the basis
of architecture and traditional ‘key characters’ (i.e.,
they lack a dense, spinescent inflorescence and possess
calyx lobes of equal length)…[and]…their inclusion adds heterogeneity at the gross-morphological level to an otherwise cohesive group,”

they are best recognized in a more broadly defined Navarretia since Gilia sect. Kelloggia may itself not be monophyletic (necessitating recognizing several genera).

Phylogeny

(Most) Navarretia is sister to Collomia. Spencer & Porter (1997) were the first to tackle species-level relationships in Navarretia, finding support for the monophyly of sects. Navarretia and Mitracarpium. Subsequent work has not changed these findings, and has confirmed that species formerly placed in Gilia sect. Kelloggia are not monophyletic. Indeed, genus circumscription may be complicated by the placement of N. sinistra which appears to be sister to Collomia + remaining Navarretia (Rose & Sytsma 2021). A relatively distant relationship of N. sinistra compared to putative close relatives was evident in the UPGMA tree of Johnson et al. (2010) but not their phylograms because they chose to root trees with N. capillaris. For the time being, I am keeping N. sinistra with other Navarretia, but this problem needs further investigation.

With regard to intersectional classification, the two mophyletic sections are supported by morphological traits. Section Navarretia is supported by having indehiscent capsules. In addition, all species except N. tagetina and N. subuligera have 2 stigma lobes and one vein per corolla lobe. Section Mitracarpium is supported by dehiscent, unilocular or 2-locular capsules with 1 seed each.

Biogeography

Taxonomy

1. Navarretia aeroides L.A. Johnson & D. Gowen
2. Navarretia atractyloides (Benth.) Hook. & Arn.
3. Navarretia breweri (A. Gray) Greene
4. Navarretia capillaris (Kell.) Kuntze
5. Navarretia cotulifolia (Benth.) Hook. & Arn.
6. Navarretia divaricata (A.Gray) Green
7. Navarretia eriocephala H. Mason
8. Navarretia filicaulis (A. Gray) Greene
9. Navarretia fossalis Moran
10. Navarretia gowenii L.A. Johnson
11. Navarretia hamata Greene
    • N. hamata Greene subsp. hamata
    • N. hamata Greene subsp. leptantha (Greene) H. Mason
    • N. hamata Greene subsp. parviloba A.G. Day
12. Navarretia heterandra H. Mason
13. Navarretia heterodoxa (Greene) Greene
14. Navarretia intertexta (Benth.) Hook.
    • Navarretia intertexta (Benth.) Hook. subsp. intertexta
    • Navarretia intertexta (Benth.) Hook. subsp. propinqua (Suksd.) A.G. Day
15. Navarretia involucrata Ruiz & Pav.*
16. Navarretia jepsonii V.L. Bailey
17. Navarretia leptalea (A. Gray) L.A. Johnson
    • N. leptalea (A. Gray) L.A. Johnson subsp. bicolor (H. Mason & A.D. Grant) L.A. Johnson
    • N. leptalea (A. Gray) L.A. Johnson subsp. leptalea
18. Navarretia leucocephala Benth.
    • N. leucocephala Benth. subsp. bakeri (H. Mason) A.G. Day
    • N. leucocephala Benth. subsp. diffusa Bjork
    • N. leucocephala Benth. subsp. leucocephala
    • N. leucocephala Benth. subsp. suksdorfii (Howell) L.A. Johnson & D. Gowen (= N. leucocephala Benth. subsp. minima (Nutt.) A.G. Day, misapplied)
    • N. leucocephala Benth. subsp. pauciflora (H. Mason) A.G. Day
    • N. leucocephala Benth. subsp. plieantha (H. Mason) A.G. Day
19. Navarretia linearifolia (Howell) L.A. Johnson
    • N. linearifolia (Howell) L.A. Johnson subsp. linearifolia
    • N. linearifolia (Howell) L.A. Johnson subsp. pinnatisecta (H. Mason & A.G. Grant) L.A. Johnson
20. Navarretia mellita Greene
21. Navarretia mitracarpa Greene
22. Navarretia minima Nutt. (= N. furnissii L.A. Johnson & L.M. Chan)
23. Navarretia modocensis L.A. Johnson & D. Gowen
24. Navarretia myersii P.S. Allen & A.G. Day
    • N. myersii P.S. Allen & A.G. Day subsp. deminuta A.G.  Day
    • N. myersii P.S. Allen & A.G. Day subsp. myersii
25. Navarretia nigelliformis Greene
    • N. nigelliformis Greene subsp. nigelliformis 
    • N. nigelliformis Greene subsp. radians (J.T. Howell) A.G. Day
26. Navarretia ojaiensis Elvin, J.M. Porter & L.A. Johnson
27. Navarretia panochensis D.Gowen & L.A. Johnson
28. Navarretia paradoxiclara L.A. Johnson & D. Gowen
29. Navarretia paradoxinota L.A. Jonson & D. Gowen
30. Navarretia peninsularis Greene
31. Navarretia prolifera Greene
    • N. prolifera Greene subsp. lutea (Brand) H. Mason
    • N. prolifera Greene subsp. prolifera
32. Navarretia prostrata (A. Gray) Greene
33. Navarretia pubescens (Benth.) Hook. & Arn.
34. Navarretia rosulata Brand
35. Navarretia saximontana S.C. Spencer
36. Navarretia setiloba Coville
37. Navarretia sinistra (M.E. Jones) L.A. Johnson
38. Navarretia squarrosa (Eschsch.) Hook. & Arn.
39. Navarretia subuligera Greene
40. Navarretia tangetina Greene
41. Navarretia torreyella L.A. Johnson & D. Gowen
42. Navarretia viscidula Benth.
43. Navarretia vividor (Jeps. & V.L. Bailey) L.A. Johnson & D. Gowen
44. Navarretia willamettensis S.C. Spencer

References

Crampton, B. (1954). Morphological and ecological considerations in the classification of Navarretia (Polemoniaceae). Madroño, 12(8), 225-238.

Day, A. G. (1993). New taxa and nomenclatural changes in Allophyllum, Gilia, and Navarretia (Polemoniaceae). Novon, 3(4), 331-340.

Grant, V., & Day, A. G. (1999). Transfer of Some Species from Gilia to Allophyllum and Tintinabulum: And the Effects of the Transfer on the Generic Definition of Gilia (Polemoniaceae). Phytologia, 84(5), 368-382.

Grant, V., & Grant, A. (1954). Genetic and taxonomic studies in Gilia: VII. The woodland Gilias. Aliso, 3(1), 59-91.

Johnson, L. A., & Soltis, D. E. (1995). Phylogenetic inference in Saxifragaceae sensu stricto and Gilia (Polemoniaceae) using matK sequences. Annals of the Missouri Botanical Garden, 149-175.

Johnson, L. A., Schultz, J. L., Soltis, D. E., & Soltis, P. S. (1996). Monophyly and generic relationships of Polemoniaceae based on matK sequences. American Journal of Botany, 83(9), 1207-1224.

Johnson, L. A., & Cairns-Heath, H. (2010). Decrypting cryptic species: morphological and molecular evidence for recognizing Navarretia linearifolia as distinct from N. sinistra (Polemoniaceae). Systematic Botany, 35(3), 618-628.

Johnson, L. A., Chan, L. M., Burr, K., & Hendrickson, D. (2012). Navarretia furnissii (Polemoniaceae), a new diploid species from the intermountain western United States distinguished from tetraploid Navarretia saximontana. Phytotaxa, 42, 51-61.

Johnson, L. A., Gowen, D., & Jensen, A. B. (2013). Cryptic speciation: distinguishing serpentine affiliated sister species Navarretia paradoxiclara and N. paradoxinota from N. intertexta (Polemoniaceae). Phytotaxa, 91(2), 27-38.

Johnson, L. A., & Gowen, D. (2017). Ex uno, multis: taxonomic revision in Navarretia divaricata (Polemoniaceae) and the recognition of four additional cryptic or near-cryptic species. PhytoKeys, (91), 39.

Porter, J. M., & Johnson, L. A. (2000). A phylogenetic classification of Polemoniaceae. Aliso, 19(1), 55-91.

Spencer, S. C., & Porter, J. M. (1997). Evolutionary diversification and adaptation to novel environments in Navarretia (Polemoniaceae). Systematic Botany, 22(4), 649-668.