Nordic Journal of Botany 30: 47–52, 2012 doi: 10.1111/j.1756-1051.2011.01330.x, © 2012 The Authors. Nordic Journal of Botany © 2012 Nordic Society Oikos Subject Editor: Henrik Ærenlund Pedersen. Accepted 6 October 2011 Polyspora huongiana sp. nov. (Theaceae) from Vietnam and notes on related species George Orel, Peter G. Wilson, Anthony S. Curry and Hong Truong Luu G. Orel (george.orel@rbgsyd.nsw.gov.au) and P. G. Wilson, Royal Botanic Gardens, Mrs Macquaries Road, Sydney, NSW 2000, Australia. – A. S. Curry, Technical and Further Education NSW, Richmond College, Locked Bag 7, Richmond, NSW 2753, Australia. – H. T. Luu, Herbarium VNM, Centre for Biodiversity and Development, Inst. of Tropical Biology, Vietnamese Academy of Science and Technology, Hochiminh City, Vietnam. A new species of Polyspora Sweet (Theaceae) endemic to the Bidoup-Nui Ba National Park, Lam Dong Province, Vietnam, is described and illustrated: Polyspora huongiana Orel, Curry & Luu. The newly described species has variably shaped, coriaceous, narrowly elliptical leaves, terminal, pedicellate, mostly solitary, rather fleshy, dark pink to red flowers, with petals in two whorls; a columnar, seamlessly fused style with 3–5 apical lobes; persistent bracteoles; and a superior 3–4 (–5) chambered ovary. The morphological evidence supports taxonomic placement in the genus Polyspora. A new name is provided and new combinations are made for some other species in the region. There now appears to be compelling molecular evidence for the division of the traditionally recognized genus Gordonia J. Ellis into a more narrowly circumscribed Gordonia s.s. in the New World and the recently resurrected Polyspora Sweet in Asia (Prince and Parks 2001, Yang et al. 2004, Bartholomew and Ming 2005). In fact, analyses of molecular data suggest that the two genera belong to different tribes: Polyspora to Theeae, and Gordonia to Gordonieae (Prince and Parks 2001, Yang et al. 2004, Prince 2007), a view first suggested by Airy-Shaw (1936) but had been foreshadowed by Pitard (1902). Significantly, the molecular evidence relies not only on cpDNA data (rbcL and matK, plus flanking spacer regions in Prince and Parks 2001), but also on nuclear DNA data (ITS1, 5.8S gene and ITS2 in Yang et al. 2004). The presented molecular data do not support the traditional view based on morphological and anatomical studies (Keng 1962, 1984), which at best provide conflicting support for tribal and generic relationships within Theaceae (Prince and Parks 2001). Further study is required to resolve questions regarding the generic boundaries between Gordonia and Laplacea Kunth in the New World, and to investigate variation within Polyspora in Asia. A few other generic segregates from Gordonia (Nabiasodendron Pit., Antheischima Korth. and Closaschima Korth.) have been recognised in Asia, but Prince (2007) considers these to be synonyms of Polyspora and we concur with this suggestion. It should be noted that, in the southeast Asian region, the species already formally transferred to Polyspora (Bartholomew and Ming 2005, Yang 2005, Ming and Bartholomew 2007) represent only a small percentage of the likely number of Polyspora species found there (Keng 1984). Accordingly, taxonomic re-evaluation of the member species of Gordonia and Polyspora, and associated genera, based on sound molecular techniques, should be undertaken, and should include a wider range of species referred to Gordonia that occur in Malesia, India and Sri Lanka. The authors of the present work, bearing in mind the need for more and wider ranging studies, find the results to date compelling and accept Polyspora as a genus distinct from Gordonia. This view has already been adopted in China (Bartholomew and Ming 2005, Yang 2005, Ming and Bartholomew 2007) and the six species of Gordonia known to occur there have already been transferred to Polyspora by Bartholomew and Ming (2005). These are as follows: P. axillaris (Roxb. ex Ker Gawl.) Sweet, P. chrysandra (Cowan) Hu ex B. M. Barthol. & T. L. Ming, P. hainanensis (Hung T. Chang) C. X. Ye ex B. M. Barthol. & T. L. Ming, P. longicarpa (Hung T. Chang) C. X. Ye ex B. M. Barthol. & T. L. Ming, P. speciosa (Kochs) B. M. Barthol. & T. L. Ming and P. tonkinensis (Pit.) B. M. Barthol. & T. L. Ming. The inclusive view of Gordonia adopted by earlier authors was based primarily on the similarity of the fruits and, particularly, the winged seeds. Choisy (1855), Airy-Shaw (1936) and Yang et al. (2004) recognised Polyspora as distinct from Gordonia based on the following kinds of characters: pedicels short and mostly multi-bracteate and sepals not abruptly distinct from the petals, spirally arranged. Keng (1962) did note a possible difference in embryo form between the American and Asian taxa of Gordonia s.l. and 47 Yang et al. (2004) noted that there was some evidence that the similarities in fruit morphology and seed shape could be due to convergence. Some of these distinctions have been contested (Sealy 1958), so further study is required to explore possible synapomorphies for the two genera. Of some 40 species of Polyspora that occur in Asia (Krüssmann 1986, IPNI 2011), six species are known to occur within the borders of Vietnam (Gagnepain 1942, Ho 1991). In this paper, a new species of Polyspora from Vietnam, Polyspora huongiana, is described. Detailed analysis of morphological traits of this plant indicates a close morphological relationship to the seven Vietnamese species previously transferred to Polyspora, as well as to other Asian species of ‘Gordonia’ that are yet to be re-assessed. Polyspora Sweet (1825, p. 205, 1826, 1830, p. 73, 1839, p. 89) Type: Polyspora axillaris Sweet. Polyspora huongiana Orel, Curry & Luu sp. nov. (Fig. 1) P. axillari affinis sed foliis anguste ellipticis, floribus manifeste pedicellatis, petalis roseis vel rubris, staminibus stylisque longioribus differt. Type: Vietnam. Lam Dong Province: Bidoup-Nui Ba National Park, 7 Jan 2010, G. Orel, A. S. Curry 0731 (holotype: VNM, isotype: NSW). Perennial, medium to large variable evergreen tree to 10.0 m high; usually sparsely, but sometimes well branched, rarely multi-stemmed, with upright habit. Twigs glabrous, mid green and shiny toward terminals, turning entirely light grey–brown on semi-mature branches; older branches grey– brown, often gnarled and covered by lichens (especially on exposed sites); mature bark smooth, with narrow longitudinal fissures, which in some areas may develop into narrow striations. Leaf petiole slightly twisted around its axis, slightly falcate and partially laterally compressed, stout, shiny, purplish–red above, purplish–brown and shiny beneath, 8.0–12.0 mm long, 2.5–4.0 mm wide, up to 3.0 mm thick, ascending at ca 45° angle to the midrib, adaxially longitudinally divided by a shallow channel that is the continuation of the adaxial primary vein; leaf lamina continues as a slightly raised, symmetric ridge on each side of the adaxial petiole. Axillary leaf buds rudimentary, dull greenish–brown, finely tomentose, slightly falcate, with sharp apex; terminal buds slightly canescent, almost triangular, slightly falcate with sharp apex, 9.0–12.0 mm long. 3.0–6.0 mm wide. Developing leaves rigid, yellowish–green, petioles ascending, adaxial lamina yellow–green, lustrous, abaxial lamina dull and of lighter colour; juvenile leaves extremely variable in size and narrow in shape, a condition that characterizes juvenile foliage of all plants seen. Mature leaves with entire leaf margin, up to 11.0–12.5 cm long, 4.0–4.8 cm wide, lamina coriaceous, slightly variable in shape, narrowly elliptic, apex variable, always shallowly emarginate, acute to acuminate, base cuneate, adaxial surface glabrous, green and shiny, lighter green and dull below, blade midrib to 2.5–3.2 mm wide 48 proximally, less than 1.0 mm distally, light green and dull, adaxially sunken, abaxially prominent, secondary venation pinnate, indistinctly brochidodromous, with up to 20 pairs of veins, adaxially sunken between two slightly raised ridges, abaxially indistinct and also sunken, tertiary veins indistinct, sparse, unevenly distributed, areolation well developed, meshes unevenly triangular-tetragonal to pentagonal and of relatively inconstant size, maximum areole dimension 8.0 ⫻ 5.0 mm, size slightly decreasing towards edge of the leaf (Hickey in Metcalfe and Chalk 1979, Roth-Nebelsick et al. 2001). Flowers axillary, pedicellate, pedicel attached towards the apex at 45° to the stem, lacking scent; flower buds round, glabrous, with sharp apex, initially green, then purplish to brown, later fading to light pink, with randomly distributed whitish areas mostly towards proximal end, 2.3–2.5 cm long, 1.5–1.7 cm wide; bud scales dark brown to purple, orbicular, concave, 5.0–7.0 mm wide, 6.0–8.0 mm long, covering one third of the proximal end; pedicel thick, 8.0–10.0 (12.0) mm long, 5.0–7.0 mm wide distally, partially covered by perules, shiny, glabrous, with red blush, entirely green when not exposed to sun, with one or two unevenly distributed, brownish, deciduous bracteoles, scale scars present; flowers dark pink to red, rather fleshy, mostly solitary, sometimes in pairs, 5.0–6.0 (7.0) cm in diameter; petals five to seven, concave, unevenly obovate, glabrous, sometimes emarginate, basally joined for 1.0–2.0 cm, otherwise free, arranged in two whorls, petal numbers in both whorls variable, the first (outer) whorl of two to three petals, 4.0–4.5 cm long, 3.5–4.0 cm wide, slightly concave, slightly asymmetric, obovate, the second (inner whorl), three to four petals, 4.0–5.0 cm long, 3.8–4.5 cm wide, slightly concave, slightly asymmetric, roughly obovate, petals of the inner whorl form a red-yellowish coloured tube that has finely haired surfaces, tube ca 10.0 mm long. Perules persistent, slightly woody, in three whorls that form a cupule 2.0–2.2 cm high, 1.8–1.9 cm wide, cupule entirely greenish–yellow, later brown on the outside, whitely hairy, inner surface green–pinkish distally, white–pinkish proximally inside, thinner at the distal end; first (outer) whorl, 1–2 purplish–green, later purplish–brown orbicular perules, glabrous and shiny on outer surfaces, inner surfaces with short white hair when juvenile, 11.0–12.0 mm long, 7.0–9.0 mm wide; second (middle) whorl, two perules arranged at a 90° angle to the perules of the first whorl, perules slightly concave, purplish–brown, orbicular, glabrous and shiny on outer surfaces, inner surfaces with short white hair when juvenile, 14.0–16.0 mm long, 17.0–19.0 mm wide; third (inner) whorl, two perules at a 90° angle to the middle whorl, perules light brown proximally, otherwise dark purplish–pink, orbicular, concave, glabrous and shiny on visible outer surfaces, inner surfaces with short white hair when juvenile, 1.8–2.0 cm long, 2.5–2.7 cm wide. Stamens 210–260, in a circular formation 2.0–4.0 cm in diameter, loosely divided into three concentric circles; filaments 2.5–3.0 cm long, finely hairy, distally seldom straight, basally joined for 3.0–6.0 mm, light yellow distally, pinkish proximally but of a lighter colour than petals, basally joined to the inner petal whorl for 8.0–10.0 mm; anthers glabrous, bright yellow, later dark yellow to brown, variable in size, 2.5–3.0 mm long, about 1.0 mm wide, dorsifixed, acuminate Figure 1. Polyspora huongiana sp. nov. (A) adult leaf, primary and secondary venation, adaxial view, (B) adult leaf, primary, secondary and tertiary venation, abaxial view, (C) adult leaf, leaf base and leaf petiole, adaxial view, (D) adult leaf, leaf base and leaf petiole, abaxial view, (E) petiole, transverse section, (F) perules, outer whorl, (G) perules, middle whorl, (H) perules, inner whorl, (I) petals, outer whorl, (J) petals, inner whorl, (K) adult flower, lateral view, (L) perules after anthesis, (M) anther, (N) style, apex, (O) adult fruit capsule, (P) seed, (Q) branch with a flowers and leaves. Drawn from the isotype G. Orel and A. S. Curry 0731 held at NSW. 49 at the distal end, very slightly cordate at proximal end, with three distinct brown striations on the adaxial surface. Style columnar, 2.2–2.6 cm long, proximally thick, of variable thickness above, consisting of three to five seamlessly fused parts, style yellowish–green, entirely hairy in juvenile state, adult style finely hairy at the base for about one third of its length, glabrous at the top; stigma divided distally for 1.0–2.0 mm into 3–5 rather indistinct apical lobes of yellowish–brown colour. Ovary superior, resting on a hard woody base, cylindrical, lightly striated, 3–4 (–5)-carpellate, yellowish–green, but sometimes pinkish in colour, densely tomentose, 8.0–10.0 mm long, 5.0–6.0 mm wide. Juvenile seed capsules cylindrical, mid green, with indistinct, unevenly distributed, brown striations, shiny, palely and thinly tomentose, with asymmetric, blunt, but distinct apex, basal scars present from the caducous calyx; mature seed capsule cylindrical to oblong, mid brown, shiny, hairy, woody and hard, 2.5–3.0 (4.5) cm long, 1.1–1.3 cm in diameter, 5-valved, each valve containing approximately three seeds, bases of valves squarely truncate, apex acute; columella persistent, 2.4–2.8 cm long. Seed mid brown, glabrous, longitudinally compressed, together with a wing 13.0–15.0 mm long and 4.0–5.0 mm wide; wing thin, roughly ellipsoid. Vietnamese species named by Gagnepain (1942), and accepted by Ho (1991) that require new combinations in Polyspora: Distribution Polyspora elliptica (Gardner) Orel, Peter G. Wilson, Curry & Luu comb. nov. Basionym: Gordonia elliptica Gardner, Calcutta J. Nat. Hist. 7 (1847, p. 448). Polyspora huongiana is known from collections made in the Bidoup-Nui Ba National Park, in Lam Dong Province, Vietnam, which is the only known locality for this species. Polyspora huongiana occurs in small groups, seldom as solitary specimens, that are scattered in the thick understory of tall, dense, cool-temperate forest, at altitudes between 1800 and 2000 m a.s.l. The new species thrives in the pockets of relatively rich, brown, well drained and sometimes rocky soils. The authors were unable to find any other specimens of P. huongiana in any Vietnamese herbarium. Conservation status A number of adult specimens were found in the area of the type locality. This species occurs in small groups, or as individual plants, these being scattered throughout the rainforest in at least two identified localities, thus indicating that it may be sporadically represented throughout the confines of the Bidoup-Nui Ba National Park. Given this situation, and a relatively small number of adult specimens, we consider the IUCN category (IUCN 2011) of ‘Vulnerable’ (Vu) to be appropriate. Phenology The new species was collected in flower in January, with the fruit maturing in February to April and the capsules dehiscing in April. Etymology The specific epithet honours Mr Le Van Huong, the director of the Bidoup-Nui Ba National Park, in Lam Dong Province, Vietnam, whose support and generosity made the collection of this new species possible. New combinations in the genus Polyspora Apart from the species already transferred by Bartholomew and Ming (2005) and Yang (2005), there are a three further 50 Polyspora bidoupensis (Gagnep.) Orel, Peter G. Wilson, Curry & Luu comb. nov. Basionym: Gordonia bidoupensis Gagnep., Notul. Syst. (Paris) 10 (1942, p. 119). Polyspora gigantiflora (Gagnep.) Orel, Peter G. Wilson, Curry & Luu comb. nov. Basionym: Gordonia gigantiflora Gagnep., Notul. Syst. (Paris) 10 (1942, p. 120). Polyspora intricata (Gagnep.) Orel, Peter G. Wilson, Curry & Luu comb. nov. Basionym: Gordonia intricata Gagnep., Notul. Syst. (Paris) 10 (1942, p. 121). Furthermore, there are other, well documented ‘Gordonia’ species from Sri Lanka (Wadhwa 1996, Yakandawala and Gunathilake 2008), Thailand (Keng 1972) and Papua New Guinea (Barker 1980), that are referable to Polyspora and we here provide the necessary new combinations: Polyspora ceylanica (Wight) Orel, Peter G. Wilson, Curry & Luu comb. nov. Basionym: Gordonia ceylanica Wight, Ill. Ind. Bot 1 (1838, p. 99). Polyspora dassanayakei (Wadhwa & Weeras.) Orel, Peter G. Wilson, Curry & Luu comb. nov. Basionym: Gordonia dassanayakei Wadhwa & Weeras., in M. D. Dassanayake & W. Clayton, (eds), Revised handbook Flora Ceylon 10 (1996, p. 392). The following Sri Lankan species requires a new name since the original epithet is preoccupied in Polyspora. The species is named for George Gardner, superintendent of the botanic garden at Peradeniya (1843–1849), who first named it: Polyspora gardneri Orel, Peter G. Wilson, Curry & Luu nom. nov. Replaced synonym: Carria speciosa Gardner, Calcutta J. Nat. Hist. 7 (1847, p. 7) (non Polyspora speciosa (Kochs) B. M. Barthol. & T. L. Ming). Based on the same type: Gordonia speciosa (Gardner) Choisy, Mém. Soc. Phys. Genève 14 (1855, p. 142). Polyspora dalglieshiana (Craib) Orel, Peter G. Wilson, Curry & Luu comb. nov. Basionym: Gordonia dalglieshiana Craib, Bull. Misc. Inform. Kew (1924, p. 87). Polyspora papuana (Kobuski) Orel, Peter G. Wilson, Curry & Luu comb. nov. Basionym: Gordonia papuana Kobuski, J. Arnold Arbor. 21 (1940, p. 136). Barker (1980) made a thorough examination of numerous specimens collected from a number of locations in New Guinea, and concluded that the previously published Gordonia papuana var. acuminata Kobuski (1940, p. 137), G. papuana var. montana Kobuski (1940, p. 138), G. brassii Kobuski (1940, p. 135), and the misapplied names G. fragrans auct. non Merr.: Diels (1922, p. 431) and G. luzonica auct. non Vidal: Melchior in Engl. and Prantl (1925, p. 137) all apply to a single taxon, G. papuana Kobuski. Barker (1980) considered Gordonia papuana Kobuski to be a ‘homogenous species showing little or no evidence of polymorphism’. Phytogeographic and taxonomic remarks Polyspora huongiana and P. axillaris, the type species of Polyspora, share a number of morphological traits. Polyspora huongiana reaches a height of up to 10.0 m, P. axillaris (Roxb. ex Ker Gawl.) Sweet, attains 7.0–10.0 m (Krüssmann 1986), or up to 9.0 m (Ming and Bartholomew 2007); both species possess glabrous juvenile branches (Krüssmann 1986, Ming and Bartholomew 2007); pubescent terminal buds (Ming and Bartholomew 2007); leathery or coriaceous leaf laminas (Ho 1991, Hsieh et al. 1996, Ming and Bartholomew 2007); similar primary and secondary leaf venation (Hsieh et al. 1996, Ming and Bartholomew 2007); pedicellate flowers (Krüssmann 1986, Hsieh et al. 1996, Ming and Bartholomew 2007); and 3–5-locular ovaries (Bentham 1861, Ming and Bartholomew 2007). Despite these similarities, P. huongiana differs from P. axillaris (Roxb. ex Ker Gawl.) Sweet in a number of fundamental morphological characters. Polyspora huongiana has petioles 0.8–1.2 cm long, not petioles 1.0–1.5 cm long (Ming and Bartholomew 2007); mature leaves that are narrowly elliptical, not oblong obtuse (Bentham 1861), oblanceolate to oblong (Krüssmann 1986), oblong, oblonglanceolate or oblanceolate (Hsieh et al. 1996), or obovate- oblong to oblanceolate (Ming and Bartholomew 2007); mature leaves 11.0–12.5 cm long and 4.0–4.5 cm wide, not 7.5–12.7 cm long (Bentham 1861), 6.0–15.0 cm long and 2.0–5.0 cm wide (Krüssmann 1986), or 6.0–14.0 cm long and 2.5–4.0 cm wide (Ming and Bartholomew 2007); dark pink to red flowers, not white (Bentham 1861, Hsieh et al. 1996, Ming and Bartholomew 2007), yellowish–white (Krüssmann 1986), or white–pink (Ho 1991); pedicel 8.0–10.0 (12.0) mm long, not very short (Bentham 1861, Krüssmann 1986), flowers nearly sessile (Hsieh et al. 1996), or pedicel 2.0–3.0 mm long (Ming and Bartholomew 2007); flowers 5.0–6.0 (7.0) cm in diameter, not almost 8.0 cm (Bentham 1861), 7.0–12.0 (Krüssmann 1986), or 7.0–10.0 cm (Ming and Bartholomew 2007); petals five to seven, not five (Hsieh et al. 1996, Ming and Bartholomew 2007); stamens 2.5–3.0 cm long, not 1.5–2.0 cm long (Hsieh et al. 1996, Ming and Bartholomew 2007); style 2.2–2.6 cm long, not 1.5–2.0 cm (Hsieh et al. 1996), or ca 2.0 cm (Ming and Bartholomew 2007); capsule 2.5–3.0 cm long, 1.1–1.3 cm in diameter, not 4.0 cm long (Ho 1991), 2.0–3.5 cm long (Hsieh et al. 1996), or 2.0–3.5 (4.0) cm long and 1.5–2.5 cm in diameter (Ming and Bartholomew 2007). Polyspora huongiana shares a number of morphological characteristics with a number of Polyspora species. The new speciees possesses narrowly elliptic mature leaves, P. elliptica has elliptic mature leaves (Yakandawala and Gunathilake 2008); stamens arranged in three concentric circles, P. papuana stamens in three rings (Barker 1980); filaments basally joined to the inner petal whorl, P. chrysandra filaments basally adnate to petals (Bartholomew and Ming 2005, Ming and Bartholomew 2007) and densely tomentose ovary, P. papuana pubescent ovary (Barker 1980). Polyspora huongiana differs from other Polyspora species in a number of important morphological characteristics. Polyspora huongiana is a tree to 10.0 m high, not to 15.0 (25.0) m high as P. longicarpa (Bartholomew and Ming Table 1. Comparison of selected vegetative characters of seven Polyspora Sweet species native to Vietnam. P. huongiana∗ P. bidoupensis∗ P. gigantiflora P. intricata P. balansae P. axillaris∗ P. tonkinensis∗ Height (m) Leaf shape Leaf apex Leaf base Petiole length (mm) to 10 20–25 6 7–8 8 7–10 12 narrowly elliptical elliptical lanceolate to oblong elliptical to lanceolate lanceolate obovate, oblong to oblanceolate lanceolate to oblanceolate acute to acuminate attenuate to obtuse shortly acuminate acuminate acuminate obtuse or emarginate obtuse cuneate acute to obtuse attenuate acute cuneate cuneate cuneate 8–12 10–15 7–8 10 5–8 10–15 8–15 Table 1a. Comparison of selected reproductive characters of seven Polyspora Sweet species native to Vietnam. P. huongiana∗ P. bidoupensis∗ P. gigantiflora P. intricata P. balansae P. axillaris∗ P. tonkinensis∗ Flower colour Pedicel length (mm) Ovary Style Capsule length (mm) dark pink to red white white white yellowish white, yellow, pinkish white, off white 8.0–10.0 (12.0) 3.0–4.0 3.0–4.0 sessile 3.0–4.0 2.0–3.0 3.0–5.0 3–5-locular 5-locular 7-locular 3-locular 3–5 locular 3–5-locular 3–5-locular 3–5 fused parts 5-sulcate basally connate 3-sulcate parts rarely united columnar, sulcate basally connate 25–30 30–50 6–7 40 30–50 40 20 References: Pitard 1902, Gagnepain 1942, Keng 1972, Krüssmann 1986, Ho 1991, Bartholomew and Ming 2005, Ming and Bartholomew 2007, ∗ ⫽ confirmed by field observation, G. Orel & A. S. Curry. 51 2005, Ming and Bartholomew 2007), or a shrub 3.0–6.0 m high as P. chrysandra (Bartholomew and Ming 2005, Ming and Bartholomew 2007); P. huongiana possesses narrowly elliptic mature leaves, not lanceolate-oblong as does P. gigantiflora (Gagnepain 1942); dark pink to red coloured flowers, not white as do P. ceylanica and P. elliptica (Yakandawala and Gunathilake 2008); flowers lacking scent, not heavily scented as does P. papuana (Barker 1980); styleconsisting of three to five seamlessly fused parts, not a 3-sulcate style as does P. intricata (Gagnepain 1942); a 3–4 (5) carpellate ovary, not seven locular ovary as does P. gigantiflora (Gagnepain 1942) and seed capsules 2.5–3.0 cm long, not 4.0 cm long as does P. intricata, or 3.0–5.0 cm long as does P. bidoupensis (Ho 1991). Table 1 compares the key features of P. huongiana with those of the other six Vietnamese species. 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