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Randi, Agusti, Wijedasa, Lahiru S., Utteridge, Timothy M.A. (2022): Lophopetalum tanahgambut, a new endemic giant tree species from peat swamp forest of Sumatera, Indonesia, with the first pseudoverticillate leaf arrangement in genus Lophopetalum (Celastraceae). Phytotaxa 573 (1): 115-122, DOI: 10.11646/phytotaxa.573.1.7, URL: http://dx.doi.org/10.11646/phytotaxa.573.1.7

2. Thrixspermum praetermissum Toolmal, Schuit. & Suddee, spec. nov. (Figs. 5–7, 11A–B). Type:— THAILAND. Eastern Thailand, Chaiyaphum Province, Phu Khieo Wildlife Sanctuary, Thung Kamang, 07 December 2020, N . Toolmal, B. Buaphong & K. Putaha 07122002 (holotype: TTM-Spirit; isotypes: BKF, QBG). Thrixspermum trichoglottis auct. non (Hook.f.) Kuntze: Seidenfaden (1988: 163); Seidenfaden (1992: 408); Huda (2007: 47); Schuiteman et al. (2008: 312); Chen et al. (2009: 469); Xu et al. (2010: 444); Gao & Liu (2014: 1084); Averyanov et al. (2016: 353); Gale et al. (2018: 170); Jin et al. (2019: 213); Misra (2019: 528); Aung et al. (2020: 103); Barbhuiya et al. (2021: 717). Sarcochilus hystrix auct. non (Blume) Rchb.f.: Grant (1895: 301). Thrixspermum hystrix auct. non (Blume) Rchb.f.: Ormerod et al. (2021: 229). Thrixspermum praetermissum is similar to T. trichoglottis in the elongate stem, mostly oblong leaves, and the 3-lobed lip with pubescent lateral lobes. It can be distinguished from T. trichoglottis by the white tepals (vs. pale yellow tepals), the broader lanceolate to elliptic dorsal-sepal 3–4 mm wide (vs. oblanceolate to elliptic dorsal-sepal 2.5–3.0 mm wide), the broader and longer lateral sepals 10–11 × 4–5 mm (vs. 8–10 × 3.5–4 mm), the broader petals 3.0– 3.5 mm wide (vs. 2.5–3.0 mm wide), the narrow conical spur 3 × 2 mm with distinctly 2-lobed at apex (vs. the broader conical spur 2.5 × 2.0 mm with indistinctly 2-lobed to obtuse at apex), lip with smaller broadly ovate to slightly suborbicular lateral lobes 3.5–4.0 × 2.0– 2.5 mm, apex rounded (vs. obovate lateral lobes, 4–6 × 3.0 mm, apex obtuse), the longer, ovate mid-lobe 1.0 × 1.5 mm, with 1 mm long capitate hairs along the apical margins only, apex erect, recurved and obtuse (vs. mid-lobe broadly triangular 1 × 2 mm, slightly concave only in the basal part, convex apically (0.5 mm), adaxially with capitate hairs but without capitate hairs along the apical margins, apex acute and decurved). Epiphytic herb. Stems patent, 8–16 cm long, with 18–20 internodes, terete, slightly laterally compressed, curved upwards in upper half, covered with the leaf sheaths, 11–12-leaved, new plants can arise from the original stem; internodes 4.0–10.5 × 1.2–3.6 mm. Roots terete, thick, elongate, 6 cm to more than 35 cm long, 0.2–1.7 mm diam., arising from the basal part of the stem and from nodes near the lowest leaf, not or sparsely branching. Leaf sheaths green, sometimes spotted or suffused with purplish red, slightly bilaterally compressed, longer than the stem internodes. Leaves green, sometimes spotted or suffused with purplish red, patent, elliptic to oblong, 1.8–4.0 × 0.6–1.5 cm, sessile, slightly narrowed towards the base, leaves on the same side of the stem 0.5–1.0 cm apart, dorsiventrally flattened, apex unequally 2-lobed with obtuse lobes, with a small mucro in the middle, thick, rigid, fleshy, coriaceous, the midrib distinct on the abaxial side. Inflorescences four to twelve per plant, patent, racemose, 1–5(10) cm long, long pedunculate, arising from the nodes at the lowest leaves and below the roots, yellowish green; peduncle terete, slightly upwards curved from the middle, 1.5–9.5 cm long, 0.8–2.5 mm diam., with 2 internodes, the basal internode somewhat shorter, 1.2–2.0 mm long, 0.5–0.8 mm diam., the terminal internode swollen distally, 1–3 cm long, broadening to 2.5 mm diam. just below rachis; peduncle scales 2, green, slightly spotted or suffused with purplish red, broadly ovate to triangular, incurved, concave, thickened, slightly boat-shaped, clasping the peduncle, 2–3 × 1 mm, apex acuminate, keeled; rachis relatively short, 5.7–8.0 mm long, depending on the age of the inflorescence, densely 4–7- flowered, with 1–2 flowers open at a time, swollen, 3.7–5.2 mm diam., clearly thicker than the peduncle. Floral bracts quaquaversal, green, slightly spotted or suffused with purplish red, broadly ovate to triangular, incurved, concave, thickened, slightly boat-shaped, strongly clasping the rachis at the base, 3 × 2 mm, apex acuminate. Pedicel-with-ovary pale yellow, cylindrical, 6-grooved, 6–8 mm long, 0.5–1.0 mm diam. Flowers resupinate, opening widely, lasting one day, membranaceous, 1.0– 2.5 cm across; tepals white, lip white, spotted with brownish orange at the basal part of the lateral lobes, at the lip between the lateral lobes, and apical margins of the mid-lobe, the spur with orange warts inside on the back wall which shine through on the outside, column and anther creamy white, pollinia bright yellow, stipe and viscidium creamy white. Dorsal sepal lanceolate to elliptic, 10 × 3–4 mm, concave, slightly boat-shaped, acute, glabrous, 5-nerved, nerves reticulate branching. Lateral sepals lanceolate, 10–11 × 4–5 mm, obliquely dilated at the lower margin, rather concave, slightly boat-shaped, with a low abaxial keel, acute, glabrous, 5-nerved, nerves reticulate branching. Petals oblanceolate, 8–9 × 3.0– 3.5 mm, narrower than the sepals, concave, slightly boat-shaped, apex acute, glabrous, 3-nerved, nerves reticulate branching. Lip rhombic-triangular in outline when spread, oblong in natural position, 3-lobed, 5–6 × 2.5–3.0 mm in natural position, 7–8 mm wide when spread, with a conical, sac-like spur at the base; spur narrowly conical, 3 × 2 mm, apex 2-lobed with obtuse lobes (0.5 × 0.7 mm), inside towards the base of the callus with large, orange, rounded warts, 1 mm diam. and densely covered with fairly long capitate hairs (0.5 mm long); lateral lobes broadly ovate to slightly suborbicular, distinctly shorter than the mid-lobe, 3.5–4.0 × 2.0– 2.5 mm, with rounded apex, erect, curving upwards and clasping the column, densely covered with 0.8–1.0 mm long capitate hairs on both surfaces and along the apical margins; mid-lobe ovate, 1.0 × 1.5 mm, somewhat concave, covered with 1 mm long capitate hairs along the apical margins, rather thick, fleshy, entire, apex obtuse, recurved; lip adaxially between the lateral lobes densely covered with long capitate hairs, glabrous abaxially, a little below the mid-lobe with a cuneate callus 1 mm long, 0.8–1 mm diam., apex bilobulate, decurved, glabrous. Column cylindrical, short, stout, 2 × 1.5 mm, laterally winged; column-foot short, broad, 1.5–2.0 × 1.5–2.0 mm. Anther suborbicular in outline, glabrous, 1.0 × 1.0 mm, the median with a longitudinal ridge. Pollinia in two pairs, those in a pair unequal, ovate, curved; the larger 0.8 × 0.5 mm; the smaller, 0.6 × 0.3 mm; stipe broadly ovate, 0.5 × 0.5 mm, concave along the median, slightly translucent; viscidium transverse-linear, 0.2 × 0.5 mm, bent into a crescent shape, slightly translucent. Fruit yellowish green, narrowly cylindrical, 8 cm long, 2.5–3.5 mm diam., with 6 longitudinal ridges. Described from spirit material. Distribution:— INDIA. Assam, Arunachal Pradesh and Meghalaya. BANGLADESH. Cox’s Bazar and Chittagong. MYANMAR. Kachin (Mohnyin), Mon (Mawlamyine), Tanintharyi (Dawei, Myeik). CHINA. Yunnan (Xishuangbanna). THAILAND. Northern: Mae Hong Son Province (Sop Ngao), Chiang Mai Province (Fang, Chiang Dao, Mae Taeng), Tak Province (Umphang), Pitsanulok Province (Nakhon Thai); North-Eastern: Phetchabun Province (Nam Nao, Thung Salaeng Luang); Eastern: Chaiyaphum Province (Phu Khieo Wildlife Sanctuary); South-Western: Kanchanaburi Province (Tha Kanun, Wangka, River Kwai, Sai Yok, Kreng Kravia, Sangkhla); Peninsular: Chumphon Province (Chumphon to Ranong), Ranong Province (Lamlieng). LAOS. Vientiane. VIETNAM. Dak Lak (Yok Don), Ninh Thuan (Ninh Phuoc) (Fig. 26). Phenology:—Flowering in January, February, April, July, August, September, October, November and December (in natural habitat, seventeen records); January, April, September and November (in cultivation, four records). Flowering is probably intermittent throughout the year, as in most species of Thrixspermum. Habitat and ecology:—Epiphyte in riverine forests, deciduous dipterocarp forest, mixed deciduous forest, forest on limestone, dry evergreen forest, secondary evergreen forest, bamboo forest, at 400–800 m elevation, locally common along streams, waterfalls, hot springs, and in the surrounding zone, growing on trunks or twigs of small trees, such as Psidium guajava L. (Myrtaceae), in exposed positions at about 1–3 meters above the ground. Conservation status:— Thrixspermum praetermissum is a widespread species distributed from North-eastern India, Bangladesh, Myanmar, southern China, Thailand, Laos to southern Vietnam, with an Extent of occurrence (EOO) of 2,288,820.461 km 2 and an Area of occupancy (AOO) of 112.000 km 2. The species is quite common locally with a large number of individuals and is widespread across the northern part of mainland southeast Asia. It is, therefore, assigned the conservation status of Least Concern (LC) according to IUCN criteria. Etymology:—From the Latin praetermissum, disregarded, in reference to the fact that this common and widespread species has usually been misidentified as T. trichoglottis (Hook.f.) Kuntze. Vernacular (Thailand):—Ueang Khao (เอื̊องขาว), Ta Khap Khao (ตะขาบขาว), Ta Khap Khao Pak Lai (ตะขาบขาวปากลาย). Additional specimens examined:— MYANMAR. Kachin, Mohnyin District, Kurzweil & Saw Lwin KL 2789, 5 May 2010, (SING s.n., not seen), Mon, Mawlamyine District, Parish 107 & 285 (K s.n., not seen), Tanintharyi, Dawei District, Ye Lwin Aung PT-7329, as T. trichoglottis (PE s.n., not seen), Myeik District, Griffith 1006, Kew Distr. 5232 (K s.n.!). THAILAND. Northern: Mae Hong Son Province, Sop Ngao, A.F.G. Kerr 266A, 02 February 1912 (K s.n.!, Seidenfaden 1988: 162 as T. trichoglottis), Chiang Mai Province, Fang District, Seidenfaden & Smitinand GT 2097 (C 8425!, 8360!, 8355!, Seidenfaden 1988: 162 as T. trichoglottis), Chiang Dao District, Ban Bing Kong, J.F. Maxwell 87-1302, 29 October 1987 (BKF 94558!, CMU 000797!, L 0597319, not seen, L 1540280!), Mae Taeng District, A.F.G. Kerr 266, 14 October 1912 (K s.n.!, Seidenfaden 1988: 162 as T. trichoglottis), N. Toolmal & P. Rakthai 22082001, 22 August 2020 (TTM 0006358!), Pong Dueat, K. Larsen, Supee S. Larsen, Chr. T. Norgaard, K. Pharsen, P. Puudjaa & W. Uerchirakan 44872, 26 November 1993 (AAU s.n.!), Mae Rim District, Queen Sirikit Botanical Garden, Orchid Nursery, S. Pumicong 12, 28 November 2005 (QBG 27088!), C. Glamwaewwong 1127, 29 August 2005 (QBG 25286!), Mueang District, JJ botanical shop, N. Toolmal & A. Promtong 26122002, 26 December 2020 (TTM 0006397!), Tak Province, Umphang District, Umphang Wildlife Sanctuary, Thi Lo Su Waterfall, S. Suddee et al. 4672, 06 April 2014 (BKF s.n.!), Pitsanulok Province, Pitsanulok to Lomsak km 80, Seidenfaden & Smitinand GT 5360 (C 8358!, Seidenfaden 1988: 162 as T. trichoglottis), Seidenfaden & Smitinand GT 5361, 12 February 1987 (C 8424!, 8394!, Seidenfaden 1988: 162 as T. trichoglottis); North-Eastern: Phetchabun Province, Nam Nao District, Nam Nao National Park, S. Suddee et al. 1799, 03 July 2003 (BKF s.n.!), Thung Salaeng Luang National Park, Seidenfaden & Smitinand GT 5511, (C 8393!, Seidenfaden 1988: 162 as T. trichoglottis); South-Western: Kanchanaburi Province, Tha Kanun, A.F.G. Kerr s.n., 23 January 1926 (K s.n.!, Seidenfaden 1988: 162 as T. trichoglottis), Wangka, A.F.G. Kerr 0299, 12 February 1926 (K s.n.!, Seidenfaden 1988: 162 as T. trichoglottis), River Kwai, C. Phengkhlai 292, 21 December 1961 (BKF 113300!), Kostermans, AJGH 733, 24 May 1946 (L 1540281!, Seidenfaden 1988: 162 as T. trichoglottis), Sai Yok, K. Larsen 8924, 23 December 1961 (C s.n.!), Seidenfaden & Smitinand GT 4323 (C 8392!, Seidenfaden 1988: 162 as T. trichoglottis), Seidenfaden & Smitinand GT 4324 (C 8362!, Seidenfaden 1988: 162 as T. trichoglottis), Kreng Kravia, C. Chermsirivathana 1775, 01 February 1971 (BK 256121!), Sangkhla, CP., BN., SS. 3052, 24 February 1975 (BKF 078295!); Peninsular: Chumphon, A.F.G. Kerr 0357, 27 January 1927 (BK 256118!, C s.n.!, Seidenfaden 1988: 162 as T. trichoglottis), Chumphon to Ranong, C. Phengkhlai 1098, 16 September 1965 (BK 42378!), Lamlieng, A.F.G. Kerr s.n., 29 December 1918 (K s.n.!, Seidenfaden 1988: 162 as T. trichoglottis), Unknown locality, O. Thaithong 546, 07 December 1988 (BCU s.n.!). LAOS. Vientiane Province, route 13 at km 50 towards Luang Prabang, A.D. Kerr 2447 (C 8421!, Seidenfaden 1988: 162 as T. trichoglottis). VIETNAM. Cao Bang Province, Ha Lang District, Municipality Thang Loi, Vicinities of Lung Sam Village, H.N. Ridley 351, 1953 (BM 000534688!), Dak Lak Province, Yok Don, L. Averyanov & T. Maisak AL 022, 14 August 2015 (LE 01076415!), Ninh Thuan Province, Ninh Phuoc District, Dinh Quang Diep s.n., 01 April 2014 (LE 01067190!), Bien Hoa, F. Evrard 61, 19 October 1920 (P 00324382!). Taxonomic notes:— Thrixspermum praetermissum is a distinctive species because of the combination of white tepals and a lip mid-lobe with 1 mm long capitate hairs along the apical margin only. It has long been confused with T. trichoglottis, from which it differs in the characters mentioned in the diagnosis, in particular, in the white flowers, the broader sepals and petals, the lip with broadly ovate to slightly suborbicular lateral lobes with rounded apex, the ovate mid-lobe with long capitate hairs along the apical margins, and an obtuse and recurved apex. The two species also have different geographical distribution ranges: T. praetermissum occurs only in the northern part of mainland South-East Asia and tropical Asia, from India, Bangladesh, China, Myanmar, Thailand, Laos to Vietnam, whereas T. trichoglottis can only be found in the southern part of mainland SE Asia and in the Malay Archipelago, from Peninsular Thailand and Malaysia to Borneo (Sarawak, Sabah) and Java (Fig. 25). Because of the white flowers with brownish orange spots on the lip, Thrixspermum praetermissum resembles T. pulchellum (Thwaites) Schltr. (Schlechter 1911: 57, based on Cylindrochilus pulchellus Thwaites 1858 –1864[1861]: 307) (Fig. 12E–F), a species from Sri Lanka, Thailand (pers. obs. Nopparut Toolmal) and Peninsular Malaysia. However, these species differ in several characters. Thrixspermum praetermissum has elliptic to oblong leaves, distinctly unequally 2-lobed at apex with obtuse lobes (vs. narrowly oblong to oblanceolate, slightly unequally 2-lobed at apex with acute lobes), inflorescences mostly shorter than the leaves or subequal, or rarely twice as long as the leaves (vs. inflorescence always distinctively longer than the leaves). Thrixspermum praetermissum has a lanceolate dorsal-sepal (vs. elliptic to oblanceolate dorsal-sepal), petals 3.0– 3.5 mm wide (vs. petals 2.0– 2.5 mm wide), ovate mid-lobe, 1.5 mm wide, covered with 1 mm long capitate hairs only along the apical margins (vs. broadly triangular mid-lobe, 3.5–4.0 mm wide, adaxially densely covered with 0.3 mm long capitate hairs, abaxially sparsely covered with short capitate hairs, and with longer capitate hairs along the margins (0.5 mm long). The distribution areas are also different: T. praetermissum, as mentioned above, is distributed only in the northern part of mainland South-East Asia and tropical Asia, whereas T. pulchellum has only been recorded from Sri Lanka, Peninsular Thailand and Peninsular Malaysia., Published as part of Toolmal, Nopparut, Suddee, Somran, Culham, Alastair, Utteridge, Timothy M. A. & Schuiteman, André, 2023, Taxonomic notes on Thrixspermum (Orchidaceae: Aeridinae), with five new species from Thailand, pp. 223-262 in Phytotaxa 601 (3) on pages 230-235, DOI: 10.11646/phytotaxa.601.3.3, http://zenodo.org/record/8141764, {"references":["Seidenfaden, G. (1988) Orchid genera in Thailand XIV. Fifty-nine vandoid genera. Opera Botanica 95: 1 - 398.","Huda, M. K. (2007) An updated enumeration of the family Orchidaceae from Bangladesh. Journal of Orchid Society of India 21 (1 - 2): 35 - 49.","Schuiteman, A., Bonnet, P., Svengsuksa, B. & Barthelemy, D. (2008) An annotated checklist of the Orchidaceae of Laos. Nordic Journal of Botany 26 (5 - 6): 257 - 316. https: // doi. org / 10.1111 / j. 1756 - 1051.2008.00265. x","Chen, S. C., Liu, Z. J., Zhu, G. H., Lang, K. Y., Tsi, Z. H., Luo, Y. B., Jin, X. H., Cribb, P. J., Wood, J. J., Gale, S. W., Ormerod, P., Vermeulen, J. J., Wood, H. P., Clayton, D. & Bell, A. (2009) Orchidaceae. In: Wu, Z. Y., Raven, P. H. & Hong, D. Y. (eds.) Flora of China, vol. 25. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis, 570 pp.","Xu, Z., Jaing, H., Ye, D. & Liu, E. (2010) The Wild Orchids in Yunnan. Yunnan Publishing Group Cooperation, Yunnan Science & Technology Press, Beijing, 500 pp.","Gao, J. & Liu, Q. (2014) Orchids of Xishuangbanna; Diversity and Conservation. China Forestry Publishing, Beijing, 237 pp.","Averyanov, L. V., Van Duy, N. O. N. G., Nguyen, K. S., Maisak, T. V., Phan, Q. T., Nguyen, P. T., Nguyen, T. T. & Truong, B. V. (2016) New species of orchids (Orchidaceae) in the flora of Vietnam. Taiwania 61 (4): 319 - 354. https: // doi. org / 10.6165 / tai. 2016.61.319","Gale, S., Kumar, P. & Phaxaysombath, T. (2018) A Guide to Orchids of Laos. Natural History Publications (Borneo), Kota Kinabalu, Malaysia, 203 pp.","Jin, X., Li, J. & Ye, D. (2019) Atlas of Native Orchids in China. Vol. 2. Henan Science and Technology Publishing House, China, 1257 pp.","Misra, S. (2019) Orchids of India; A Handbook. Bishen Singh Mahendra Pal Singh, Dehra Dun, India, 652 pp.","Aung, Y. L., Mu, A. T., Aung, M. H., Liu, Q. & Jin, X. (2020) An annotated checklist of Myanmar orchid flora. PhytoKeys 138: 49 - 112.","Barbhuiya, H. A., Verma, D., Dey, S. & Salunkhe, C. K. (2021) An Illustrated Guide to the Orchids of Assam. Balipara foundation, Assam, India, 806 pp.","Grant, B. (1895) The Orchids of Burma. Hanthawaddy Press, Rangoon, 424 pp.","Ormerod, P., Kurzweil, H. & Watthana, S. (2021) Annotated list of Orchidaceae for Myanmar. Phytotaxa 481 (1): 1 - 262. https: // doi. org / 10.11646 / phytotaxa. 481.1.1","Thwaites, G. H. K. (1858 - 1864) Enumeratio Plantarum Zeylaniae. Dulau & Co., London."]}

Toolmal, Nopparut, Suddee, Somran, Culham, Alastair, Utteridge, Timothy M. A., Schuiteman, André (2023): Taxonomic notes on Thrixspermum (Orchidaceae: Aeridinae), with five new species from Thailand. Phytotaxa 601 (3): 223-262, DOI: 10.11646/phytotaxa.601.3.3, URL: http://dx.doi.org/10.11646/phytotaxa.601.3.3

1. Thrixspermum alboluteum Toolmal, Schuit. & Culham, spec. nov. (Figs. 1–3, 4A–B). Type:— THAILAND. South-Western Thailand, Phetchaburi Province, Kaeng Krachan National Park, Ban Krang Camp, 312 m, 20 December 2020, N . Toolmal, S. Raksue & W. Tanming 20122001 (holotype: TTM-Spirit; isotypes: BKF, QBG). Thrixspermum musciflorum auct. non A.S. Rao & J. Joseph: Seidenfaden (1988): 166, Fig. 101, Pl. XVIIb. Thrixspermum alboluteum is distinguished from T. formosanum by the distinct concave triangular mid-lobe with emarginate apex, covered with long clavate hairs adaxially and in the apical part (vs. indistinct mid-lobe with glandular hairs adaxially), the obliquely obovate lateral lobes 4.0–5.0 mm long with rounded apex (vs. triangular 1.5–3.0 mm long with obtuse apex), bright yellow tepals, lip white, with brownish orange spots on the sac, and with scattered small orange warts inside the sac (vs. white tepals, lip white, marked with pinkish lines, with two orange-yellow bars along the apical margin, and without warts). Epiphytic herb. Stems patent, 3.5–8.0 cm long, with 5–14 internodes, terete, slightly laterally compressed, curved upwards in upper half, covered with the leaf sheaths, 4–13-leaved; internodes 1.2–4.4 × 1.2–3.6 mm. Roots terete, thick, elongate, 4 cm to more than 30 cm long, 0.5–2.4 mm diam., arising from the basal part of the stem and from nodes opposite the leaves, not or sparsely branching. Leaf sheaths green, spotted or suffused with purplish red, slightly bilaterally compressed, longer than the stem internodes. Leaves green, spotted or suffused with purplish red, patent, narrowly oblong to linear, 12–60 × 3–7 mm, sessile, slightly narrowed towards the base, leaves on the same side of the stem 1.4–7.0 mm apart, dorsiventrally flattened, conduplicate, V-shaped in cross-section, apex unequally 2-lobed with sharply acute lobes, with a small mucro in the middle, thick, rigid, fleshy, coriaceous, the midrib distinct on the abaxial side. Inflorescences one to eight per plant, patent, racemose, 2–6 cm long, long pedunculate, longer than leaf, arising from the nodes at the opposite side of the leaves, green, slightly spotted purplish red; peduncle slender, slightly upwards curved from the middle, 1.5–5 cm long, 0.4–2.0 mm diam., with 2–3 internodes, the basal internode somewhat shorter, 0.5–2.0 cm long, 0.4–0.5 mm diam., the middle internode longer, 1.5–4.0 cm long, 0.4–1.0 mm diam., the terminal internode swollen distally, 0.5–2.3 cm long, broadening to 2.0 mm diam. just below rachis; peduncle scales 2–3, green, broadly ovate to triangular, incurved, concave, thickened, slightly boat-shaped, clasping the peduncle, 1.2–2.0 × 0.8– 1.5 mm, apex acute, keeled; rachis relatively short, 0.3–1.2 cm long, depending on the age of the inflorescence, densely 4–17-flowered, with one flower open at a time, swollen, 3–6 mm diam., clearly thicker than the peduncle. Floral bracts quaquaversal, green, broadly ovate to triangular, incurved, concave, thickened, slightly boat-shaped, clasping the rachis, 1.5–2.0 × 1.0– 1.5 mm, apex acute, keeled. Pedicel-with-ovary yellowish green, cylindrical, 6-grooved, 2.5– 7.0 mm long, 1.0 mm diam. Flowers resupinate, opening widely, lasting only one day, membranaceous, 0.8–1.2 cm across, mildly sweet-scented; tepals bright yellow, lip white, spotted with brownish orange on both surfaces of the sac and at apex of the callus, the sac with orange warts inside on the back wall which shine through on the outside, column and anther white, pollinia bright yellow, stipe and viscidium creamy white. Dorsal sepal obovate to elliptic, 3.5–8.0 × 2–4 mm, concave, slightly boat-shaped, apex obtuse, glabrous, 5-nerved, nerves reticulate branching. Lateral sepals broadly ovate, subfalcate, 4–7 × 3–5 mm, obliquely dilated at the lower margin, slightly concave, with a low abaxial keel, the base broadly connected with the column-foot, obtuse, glabrous, 5-nerved, nerves reticulate branching. Petals oblanceolate, 4.4–4.5 × 1.8–2.0 mm, slightly oblique, curving downward from the middle, shorter and narrower than the sepals, slightly concave, obtuse, glabrous, 3-nerved, nerves reticulate branching. Lip suborbicular in outline when spread, 3-lobed, 5–7 × 2.0– 3.5 mm in natural position, 6–8 mm wide when spread, with a broad, sac-like spur at the base; spur oblong-conical, 2.0–2.2 × 1.5–2.5 mm, apex shallowly bilobulate with obtuse lobules (0.3 × 1 mm), inside towards the base of the callus with scattered small orange warts, and densely covered with long clavate hairs (0.5 mm long) towards the lip blade; lateral lobes obliquely obovate, distinctly surpassing the mid-lobe, 4–5 × 3 mm, with rounded apex, erect, curving forwards and bent inwards, clasping the column, adaxial surface sparsely covered with 0.5 mm long clavate hairs in the basal part and along the apical margins, abaxial surface glabrous; mid-lobe short, broadly triangular to rounded, 0.5–1.0 × 2–3 mm, somewhat concave, densely covered with 0.5 mm long clavate hairs on the adaxial surface and along the margins, rather thick (1.0– 1.5 mm), fleshy, entire, apex emarginate (each lobule 0.5 × 1.5 mm); lip adaxially between the lateral lobes sparsely covered with long clavate hairs, glabrous abaxially, a little below the mid-lobe with a trapeziform callus 1.0– 1.5 mm long, 1–2 mm diam., apex bilobulate, decurved. Column cylindrical, short, stout, 2 × 1.5–2.0 mm, laterally winged; column-foot short, broad, 1.0–2.5 × 1.5–2.5 mm. Anther suborbicular in outline, glabrous, 1.0 × 1.2 mm. Pollinia in two pairs, those in a pair unequal, elliptic, curved; the larger 0.8 × 0.5 mm; the smaller, 0.6 × 0.4 mm; stipe broadly ovate, 0.5× 0.5 mm, concave along the median, slightly translucent; viscidium transverse-linear, 0.2 × 0.5 mm, bent into a crescent shape, slightly translucent. Fruit green, narrowly cylindrical, 70 mm long, 4 mm diam., with 6 longitudinal ridges. Described from living plants and flowers, and spirit material. Distribution:— THAILAND. Eastern: Nakhon Ratchasima Province (Khao Yai National Park); South-Western: Uthai Thani Province (Huai Kha Khaeng Wildlife Sanctuary); Phetchaburi Province (Kaeng Krachan National Park); Prachuap Khiri Khan Province (Khan Kra Dai) (Fig. 25). Phenology:—Flowering in January, March, April and May (in natural habitat, four records); April (in cultivation, one record). Flowering is probably intermittent throughout the year, as in most species of Thrixspermum. Habitat and ecology:—Epiphyte in dry evergreen and mixed deciduous forests, at 300–600 m elevation, locally common along streams and surrounding zones, growing on twigs of small trees, such as Lagerstroemia floribunda Jack (1820: 509) (Lythraceae) and (introduced) Psidium guajava L. (Linnaeus 1753: 470) (Myrtaceae), in exposed positions at about 1–3 meters above the ground. Conservation status:— Thrixspermum alboluteum has been recorded from four localities in Eastern Thailand from Khao Yai National Park and South-Western Thailand, namely from the Huai Kha Khaeng Wildlife Sanctuary, Kaeng Krachan National Park and Khan Kra Dai Cave, with an Extent of occurrence (EOO) of 49,773.942 km 2 and an Area of occupancy (AOO) of 16.000 km 2. Although the species occurs in a strictly protected area in Khao Yai National Park and Kaeng Krachan National Park, it has a very small known population there of less than 10 mature individuals. The natural habitat in Kaeng Krachan National Park was also destroyed by being developed into a campsite and visitor centre, and visitors also collected the plants. It is, however, possible that the new species can be found distributed in other similar habitats in both sites. Khan Kra Dai Cave is currently being developed for the local temple; it is surrounded by plantations and is becoming more popular among tourists, all of which poses a considerably threat to the population of this species. However, it seems to be fairly common in Huai Kha Khaeng Wildlife Sanctuary, with more than 1,000 mature individuals present in several places, located in a diverse forest of the wildlife sanctuary and with strict protection (Priwan Srisom and Salil Sittisatjathum, pers. comm.). It is, therefore, provisionally assigned the conservation status of Vulnerable (VU) according to IUCN criteria (Vulnerable: B1a, c; C2a; D1, 2). More insight into the distribution of this species is needed for a reliable assessment. Etymology:—From the Latin album, white, and luteum, yellow, referring to the yellow tepals and the mainly white lip. Vernacular (Thailand):— ตะขาบเหลืองตะนาวศรี (Takhap Lueang Tanao Si), ตะขาบเหลืองปากหยัก (Takhap Lueang Pakyak). Additional specimens examined:— THAILAND. Eastern: Nakhon Ratchasima Province, Pak Chong, Khao Yai National Park, Cumberlege 526 (C 8433!, K 24716!, Seidenfaden 1988: 166 as T. musciflorum), Cumberlege 527 (C 8428!, K 27388!, Seidenfaden 1988: 166 as T. musciflorum), Haew Suwat Waterfall, Seidenfaden & Smitinand GT 5790 (C 8353!, 8354!, Seidenfaden 1988: 162 as T. trichoglottis); South-Western: Uthai Thani Province, Huai Kha Khaeng Wildlife Sanctuary, K.S. s.n., 03 April 1991 (BCU s.n.!), Phetchaburi Province, Kaeng Krachan National Park, S. Raksue 79, 16 April 2008 (BKF s.n.!), Prachuap Khiri Khan Province, Khan Kra Dai, Put 2318, 16 January 1929 (C 8379!; K s.n.!, Seidenfaden 1988: 166 as T. musciflorum), A.F.G. Kerr 0736, 21 March 1929 (K s.n.!, Seidenfaden 1988: 166 as T. musciflorum). Taxonomic notes:— Thrixspermum alboluteum may be recognised by the combination of the obliquely obovate lateral lobes of the lip surpassing the triangular, concave and emarginate mid-lobe, the long clavate hairs on the lip, yellow flowers with a white lip, and orange warts inside the spur. It is morphologically similar to T. formosanum (Fig. 4E–F), a species from India, southern China, North Vietnam and Taiwan (Lin & Hsu 1977, Chen et al. 2009, the Editorial Committee of the Flora of Taiwan 2000, Lin & Wang 2014, Gogoi & Yonzone 2015, Kaliamoorthy & Saravanan 2019, Khanal et al. 2022), because of its small stature with oblong or lanceolate to linear leaves, inflorescences longer than the leaves, and sepals and petals similarly shaped; it differs in having yellow flowers, a lip with brownish orange spots and orange warts, a distinct mid-lobe with emarginate apex, and obovate lateral lobes. Having critically compared the original descriptions and the type specimens of T. formosanum (T. Kawakami & N. Mori s.n., Formosa, 1907, K 000891322!, type of Sarcochilus formosanus Hayata) and T. musciflorum (Joseph 45621A, between Umran & Umsaw beside the Gauhati-Shillong highway, Nongpoh, Meghalaya, India, 23 July 1966, ASSAM 0000000209!, image seen) and the relevant literature of both species, we conclude that the two taxa are conspecific; they agree in being small plants with stems 1.5–3 cm long, white flowers 1.0– 1.2 cm across, an obovate to elliptic dorsal-sepal, ovate lateral-sepals, oblanceolate petals, a white lip, marked with pinkish to brownish stripes, triangular lateral lobes, and an indistinct mid-lobe with orangish markings and glandular hairs. In India and Bhutan, T. formosanum has often been identified as T. musciflorum (Rao & Joseph 1969; Kataki 1986; Chowdhery 1998; Bose & Bhattacharjee 1999; Dalström et al. 2017; Misra 2019; Barbhuiya et al. 2021). We also find no significant differences between T. formosanum and T. musciflorum var. nilagiricum Joseph & Vajravelu (1981). In contrast, the species we here describe as T. alboluteum had been misidentified as T. musciflorum by Seidenfaden 1988. His drawing, taxonomic notes and photographs (C-SEIDENFADEN no. 24-157!, 24-158!, 24-159!, 24-161!, 24-162!, 24-163!, 24-192!, 24- 193!, 24-194!) perfectly match our plant from Kaeng Krachan National Park. We also note that the species illustrated as T. musciflorum in Singh et al. (2019: 492) is T. indicum Vik.Kumar, D.Verma & A.N.Rao (Kumar et al. 2017). Thrixspermum alboluteum is also similar to T. patkaiense K. Gogoi (Gogoi 2022: 9, as ‘ patkaiensis ’), a recently described species from north-eastern India, which also occurs in central Laos (Averyanov 2018, as T. hystrix auct. non (Blume) Rchb.f.), Myanmar (photos by H. Kurzweil seen), and Thailand (pers. obs. Nopparut Toolmal). Like T. alboluteum, T. patkaiense (Fig. 4C–D) has yellow tepals but it has a yellow lip marked with longitudinal purplish red stripes on both surfaces of the lateral lobes towards the spur, the mid-lobe yellowish with an orange band along the apical margins, and a callus that is distinctly raised at the apex (vs. a white lip with different markings, see description, and a nearly flat callus). In T. alboluteum the lateral lobes are obovate and broadly rounded (vs. broadly ovate), the mid-lobe is densely covered with long capitate hairs on the adaxial surface and along the margin but not abaxially (vs. covered on both surfaces). The spur of T. alboluteum differs from that of T. patkaiense in being proportionally narrower, 2.0–2.2 × 1.5–2.5 mm (vs. 2.5 × 3.0– 4.2 mm). Both species have orange warts inside the spur., Published as part of Toolmal, Nopparut, Suddee, Somran, Culham, Alastair, Utteridge, Timothy M. A. & Schuiteman, André, 2023, Taxonomic notes on Thrixspermum (Orchidaceae: Aeridinae), with five new species from Thailand, pp. 223-262 in Phytotaxa 601 (3) on pages 225-230, DOI: 10.11646/phytotaxa.601.3.3, http://zenodo.org/record/8141764, {"references":["Seidenfaden, G. (1988) Orchid genera in Thailand XIV. Fifty-nine vandoid genera. Opera Botanica 95: 1 - 398.","Linnaeus, C. (1753) Species Plantarum, vol. 1. Holmiae, Impensis Laurentii Salvii, 560 pp.","Lin, T. P. & Hsu, C. C. (1977) The genus Thrixspermum Lour. of Taiwan (Orchidaceae). Taiwania 22 (1): 59 - 72.","Chen, S. C., Liu, Z. J., Zhu, G. H., Lang, K. Y., Tsi, Z. H., Luo, Y. B., Jin, X. H., Cribb, P. J., Wood, J. J., Gale, S. W., Ormerod, P., Vermeulen, J. J., Wood, H. P., Clayton, D. & Bell, A. (2009) Orchidaceae. In: Wu, Z. Y., Raven, P. H. & Hong, D. Y. (eds.) Flora of China, vol. 25. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis, 570 pp.","Editorial Committee of the Flora of Taiwan. (2000) Flora of Taiwan, vol. 5 Angiosperms Monocotyledon s (2 nd ed.). Department of Botany, National Taiwan University, Taipei, Taiwan, 1143 pp.","Lin, W. M. & Wang, Y. F. (2014) The wild orchids of Taiwan an illustrated guide. KBCC press, Taiwan, 923 pp.","Gogoi, K. & Yonzone, R. (2015) Thrixspermum formosanum (Hayata) Schltr. (Orchidaceae) from Karbi Anglong (Assam): A new record for India. The MIOS Journal 16 (1): 11 - 16.","Kaliamoorthy, S. & Saravanan, T. S. (2019) Additions to the orchid flora of Peninsular India. Rheedea 29 (4): 319 - 322. https: // dx. doi. org / 10.22244 / rheedea. 2019.29.4.05","Khanal, M., Chettri, M., Kumar, D., Chhetri, P. & Rai, S. K. (2022) Thrixspermum formosanum (Hayata) Schltr. (Orchidaceae) - A new record for the state flora of Sikkim, India. Pleione 16 (3): 345 - 347.","Rao, A. S. & Joseph, J. (1969) A new orchid species from K. & J. Hills, Assam - Thrixspermum muscaeflorum A. S. Rao & Joseph. Bulletin of the Botanical Survey of India 11 (1 - 2): 123 - 125.","Kataki, S. K. (1986) Orchids of Meghalaya. Government of Meghalaya, Shillong, 258 pp.","Chowdhery, H. J. (1998) Orchid Flora of Arunachal Pradesh. Bishen Singh Mahendra Pal Singh, India, 824 pp.","Bose, T. K., Bhattacharjee, S. K., Das, P. & Basak, U. C. (1999) Orchids of India, Second Edition. Naya Prokash, Calcutta, India, 570 pp.","Dalstrom, S., Gyeltshen, C. & Gyeltshen, N. (2017) A Century of New Orchid Records in Bhutan. The National Biodiversity Centre, Ministry of Agriculture and Forests, Royal Government of Bhutan, Serbithang, Thimphu, Bhutan, 210 pp.","Misra, S. (2019) Orchids of India; A Handbook. Bishen Singh Mahendra Pal Singh, Dehra Dun, India, 652 pp.","Barbhuiya, H. A., Verma, D., Dey, S. & Salunkhe, C. K. (2021) An Illustrated Guide to the Orchids of Assam. Balipara foundation, Assam, India, 806 pp.","Joseph, J. & Vajravelu, E. (1981) Thrixspermum muscaeflorum var. nilagiricum Joseph & Vajravelu, a new variety from Nilgiri Hills, South India. Indian Forester 107 (10): 648 - 651.","Singh, S. K., Agrawala, D. K., Jalal, J. S., Dash, S. S., Mao, A. A. & Singh, P. (2019) Orchids of India - A Pictorial Guide. Botanical Survey of India, Kolkata, 547 pp.","Kumar, V., Verma, D. & Rao, A. N. (2017) Thrixspermum indicum (Orchidaceae), a new species from Northeast India. Phytotaxa 292: 79 - 84.","Gogoi, K. (2022) Thrixspermum patkaiensis sp. nov. (Vandae: Aeridinae) from Assam, Northeast India. Lankesteriana 22 (1): 9 - 16. https: // doi. org / 10.15517 / lank. v 22 i 1.50589","Averyanov, L. V., Averyanova, A. L., Sinh, N. K., Orlov, N. L., Maisak, T. V. & Tien, N. H. (2018) New and rare orchid species (Orchidaceae) in the flora of Cambodia and Laos. Novitates Systematicae Plantarum Vascularium 49: 24 - 41. https: // doi. org / 10.31111 / novitates / 2018.49.24"]}

3. Thrixspermum trichoglottis (Hook.f.) Kuntze (1891: 682); Schlechter (1911: 57); Smith (1921: 320); Holttum (1964: 611); Comber (1990: 322); Comber (2001: 955); Wood et al. (2011: 553) (Figs. 8–11, 12C–D) — Sarcochilus trichoglottis Hook.f. (1890: 39); Hooker (1890: 2123).— Dendrocolla trichoglottis (Hook.f.) Ridley (1896: 381). Type: Singapore, icon. Ridley s.n. (lectotype K!, here designated). Epitype (here designated): Peninsular Malaysia, Pahang, Tembeling, October 1929, C.E. Carr 185 (K s.n.!). Former syntypes: Malaysia, Perak, King’s Collector 5934 (K!), icon. Scortechini s.n. (K!). Epiphytic herb. Stems patent, 10–20 cm long, with 11–23 internodes, terete, slightly laterally compressed, curved upwards in upper half, covered with the leaf sheaths, 7–17-leaved; internodes 2.8–15.0 × 1.7–3.6 mm. Roots terete, thick, elongate, 9 cm to more than 20 cm long, 0.4–1.8 mm diam., arising from the basal part of the stem and from nodes opposite the leaves or near the lowest leaf, not or sparsely branching. Leaf sheaths green, slightly bilaterally compressed, longer than the stem internodes. Leaves green, patent, oblong, 3–7 × 0.7–1.8 cm, sessile, slightly narrowed towards the base, leaves on the same side of the stem 0.5–4.0 cm apart, dorsiventrally flattened, apex unequally 2-lobed with obtuse lobes, with a small mucro in the middle, thick, rigid, fleshy, coriaceous, the midrib distinct on the abaxial side. Inflorescences one to seven per plant, patent, racemose, 7–12 cm long, long pedunculate, equally or slightly longer than leaf, arising from the nodes at the lowest leaves and below the roots, yellowish green; peduncle terete, slightly upwards curved from the middle, 6–9 cm long, 0.7–2.3 mm diam., with 2–3 internodes, the basal internode fairly short, stout, c. 3 mm long, 0.7–1.5 mm diam., the middle internode normally longer, 2 cm long, 0.9 mm diam., the terminal internode swollen distally, 3.5–5.5 cm long, broadening to 2.3 mm diam. just below rachis; peduncle scales 2–3, yellowish green, broadly ovate to triangular, incurved, concave, thickened, slightly boat-shaped, clasping the peduncle, 2.2–3.0 × 0.5–1.4 mm, apex acuminate, keeled; rachis relatively short, 0.5–1.0 cm long, depending on the age of the inflorescence, densely 7–11-flowered, with 1–2 flowers open at a time, swollen, 3.5–6.3 mm diam., clearly thicker than the peduncle. Floral bracts quaquaversal, green, broadly ovate to triangular, incurved, concave, thickened, slightly boat-shaped, strongly clasping the rachis for nearly half of its length, 2.2–4.8 × 1.5–2.5 mm, apex acuminate to caudate, keeled. Pedicel-with-ovary pale yellow, cylindrical, 6-grooved, 6–8 mm long, 0.8–1.0 mm diam. Flowers resupinate, opening widely, lasting one day, membranaceous, 1.5–2.0 cm across; tepals pale yellow, lip yellow, spotted with brownish orange on both surface at the basal part of the lateral lobes, between the lateral lobes, at the basal part of the mid-lobe, and at the apex of the callus, the spur with orange warts inside on the back wall which shine through on the outside, column pale yellow, anther creamy white, pollinia bright yellow, stipe and viscidium creamy white. Dorsal sepal oblanceolate to elliptic, 8–10 × 2.5–3.0 mm, concave, slightly boat-shaped, somewhat attenuate at the base, acute, glabrous, 5-nerved, nerves reticulate branching. Lateral sepals lanceolate, 8–10 × 3.5–4 mm, obliquely dilated at the lower margin, concave, slightly boat-shaped, with a low abaxial keel, acute, glabrous, 5-nerved, nerves reticulate branching. Petals oblanceolate, 7.5–9.0 × 2.5–3.0 mm, narrower than the sepals, concave, slightly boat-shaped, acute, glabrous, 3-nerved, nerves reticulate branching. Lip rhombic-triangular in outline when spread, oblong in natural position, 3-lobed, 5–6 × 2.5–3.0 mm in natural position, 7–8 mm wide when spread, with a conical, sac-like spur at the base; spur broadly conical, 2.5 × 2.0 mm, apex obtuse, inside towards the base of the callus with large, orange, rounded warts, 1 mm diam. and densely covered with fairly long capitate hairs (0.5 mm long); lateral lobes obovate, distinctly shorter than the mid-lobe, 4–6 × 3 mm, with obtuse apex, erect, curving upwards and clasping the column, densely covered with 0.8–1.0 mm long capitate hairs on both surfaces and along the apical margins; mid-lobe short, broadly triangular, 1 × 2 mm, slightly concave at the basal part, convex at apical part (0.5 mm), glabrous or sparsely covered with 0.8–1.0 mm long capitate hairs on the adaxial surface, rather thick, fleshy, entire, apex acute, decurved; lip adaxially between the lateral lobes densely covered with long capitate hairs, glabrous abaxially, a little below the mid-lobe with a cuneate callus 1.5 mm long, 1 mm diam., apex bilobulate, decurved, glabrous. Column cylindrical, short, stout, 2.0–3.0 × 1.5–2.0 mm, laterally winged; column-foot short, broad, 2.0 × 1.5–2.0 mm. Anther suborbicular in outline, glabrous, 1.0 × 1.0 mm, the median with a longitudinal ridge. Pollinia in two pairs, those in a pair unequal, ovate, curved; the larger 0.8 × 0.5 mm; the smaller, 0.6 × 0.3 mm; stipe broadly ovate, 0.5 × 0.5 mm, concave along the median, slightly translucent; viscidium transverse-linear, 0.2 × 0.5 mm, bent into a crescent shape, slightly translucent. Fruit yellowish green, narrowly cylindrical, 6–8 cm long, 3.0 mm diam., with 6 longitudinal ridges. Described from living plants and flowers, and spirit material. Distribution:— THAILAND. Peninsular: Narathiwat Province. SINGAPORE. Island Archipelago. MALAYSIA. Peninsular: Pahang, Kuala Lipis, Kulim, Kota Tinggi; Borneo: Sarawak, Kapit; Sabah, Sandakan, Ulu Dusun, Kota Tinggi. INDONESIA. Sumatra: West Coast, Pajokumbuh; Java: Bogor. (Fig. 26). Phenology:—Flowering in January, February, March, July, August, September, October (in natural habitat, ten records); March (in cultivation, three records). Flowering is probably intermittent throughout the year, as in most species of Thrixspermum. Habitat and ecology:—Epiphyte in orchards and along streams, 100–150 m elev., commonly found on branches of trees, including Psidium guajava L. (Myrtaceae) and Baccaurea motleyana (Müll. Arg.) Müll.Arg. (Müller Argoviensis 1866: 461) (Phyllanthaceae) at about 1–2 meters above the ground. Restricted to shady areas and somewhat exposed positions on small trees. Conservation status:— Thrixspermum trichoglottis (Hook.f.) Kuntze is a widespread species distributed from Southern Thailand, Malaysia (Peninsular, Borneo, Sarawak and Sabah), and Indonesia (Sumatra, Java), with an Extent of occurrence (EOO) of 1,516,886.346 km 2 and an Area of occupancy (AOO) of 60.000 km 2. As the species is quite common locally and can be found in large numbers of individuals in many sites, and is widespread from the southern part of Thailand to Java and Borneo, it is assessed as Least Concern (LC) according to IUCN criteria. Vernacular (Thailand):—Ta Khap Lueang Pak Lai (ตะขาบเหลืองปากลาย). Additional specimens examined:— THAILAND. Peninsular: Narathiwat Province, Sukhirin District, Phu Khao Thong Subdistrict, N . Toolmal, A. Baka & W. Tanming 28102001, 28 October 2020 (TTM 0006374!), Kalubee Subdistrict, I Jue Rao village, N . Toolmal, A. Baka & W. Tanming 28102002, 28 October 2020 (TTM 0006375!), Phu Khao Thong Subdistrict, N . Toolmal, A. Baka & W. Tanming 28102003, 28 October 2020 (TTM 0006376!). SINGAPORE. Ridley H. N . s.n., 1891 (K 000891299; syntype). MALAYSIA. Peninsular Malaysia, H. N . Ridley s.n., 1935 (K s.n.!), Pahang, Kuala Lipis, C. E . Carr K135, September 1929 (K 13824!), Kota Tinggi, Jalan Sg. Kemang, M . Shah & Noor. MS. 857, 28 September 1959 (K s.n.!, L 1540175!), Kulim, Ulu Paip, T . Roelfsema, APTM. Vogel, MMJ van. Balgooy s.n. (L 0770319, not seen), Borneo, J . Motley 484, August 1859 (K s.n.!), Sarawak, H. N . Ridley s.n., June 1915 (K s.n.!), Kapit, Upper Rejang River, J. & M. S . Clemens 1164, 1929 (K s.n.!), Clemens, J & Clemens, MS 21164, 01 January 1929 (L 0598061!, L 1540177!, L 1540178!), Unknown s.n. (BM 000534691!), Sabah, Sandakan, Ulu Dusun, A . Lamb SAN 84149 (K s.n.!), A . Lamb AL1166 / 89, 25 August 1989 (K s.n.!). SINGAPORE. Unknown locality, H. N . Ridley s.n., August 1891 (BM 000534669!), H. N . Ridley s.n., 15 February 1890 (BM 000534670!), H. N . Ridley s.n., 1891 (BM 000534671!), Hallow Road. Archipel. Ind., Unknown s.n. (L 1540176!). INDONESIA. Java, J. J . Smith s.n. (K s.n.!), Buitenzorg, Tegal Sapi, Bakhuizen van den Brink Jr, RC 1499, 23 July 1922 (L 1469180!), Sumatra, Posthumus 1042 (L 1540181!). UNKNOWN LOCALITY. Kartamah s.n. (L 1540180!). Taxonomic notes:—Although Thrixspermum trichoglottis is most similar to T. praetermissum (see the comparison above), it has also been confused with T. hystrix (Blume) Rchb.f. (Reichenbach 1874: 145, based on Dendrocolla hystrix Blume 1825: 291) first described from Bogor, West Java, Indonesia, which also has pale yellow tepals. However, T. trichoglottis is distinguished by having inflorescences as long as or slightly longer than the leaves, 7–12 cm long (vs. inflorescences twice as long as the leaves, 6.5–25 cm), an obtuse spur apex (vs. spur apex distinctly bilobed), the mid-lobe adaxially sparsely covered with long capitate hairs (vs. mid-lobe adaxially densely covered with long clavate hairs). Thrixspermum trichoglottis was described on the basis of a sterile specimen (King’s Collector 5934) and two drawings of poor quality by Scortechini and Ridley. Since several floral characters cannot be inferred from the existing type material, we here designate icon. Ridley s.n. (K s.n.!) as a lectotype, as it is the only type material that shows some floral details. To help fix the application of the name T. trichoglottis, we select C. E. Carr 185 (K s.n.) as an epitype, as this specimen was collected in the same floristic region as the type and because it has some flowers left. Although once reportedly very common in Singapore (Ridley, in sched.), it is currently considered Critically Endangered there (Yam 2013: 118). We note that the species reported as T. trichoglottis in Ong (2011: 95) and Ong et al. 2011 (2011: 163, the upper right figure) is T. pulchellum. Thrixspermum album (Ridl.) Schltr. (Schlechter 1911: 56, based on Dendrocolla alba Ridl. 1905: 191) has been included in the synonymy of T. trichoglottis (Seidenfaden & Wood, 1992). Having carefully examined the protologues and type specimens of T. album (H. N. Ridley 14130, Seberang Perai Selatan, Pulau Pinang, Malaysia, 1907, K s.n.!, BM 000534632!, type of Dendrocolla alba Ridl.) and T. pulchellum (Thwaites C.P. 2354 K 000891314!, type of Cylindrochilus pulchellus Thwaites), we consider that T. album matches T. pulchellum in all relevant characters. Therefore, we transfer T. album from the synonymy of T. trichoglottis to that of T. pulchellum., Published as part of Toolmal, Nopparut, Suddee, Somran, Culham, Alastair, Utteridge, Timothy M. A. & Schuiteman, André, 2023, Taxonomic notes on Thrixspermum (Orchidaceae: Aeridinae), with five new species from Thailand, pp. 223-262 in Phytotaxa 601 (3) on pages 235-242, DOI: 10.11646/phytotaxa.601.3.3, http://zenodo.org/record/8141764, {"references":["Kuntze, C. E. O. (1891) Revisio Generum Plantarum, vol. 2. Arthur Felix, Leipzig, 637 pp.","Smith, J. J. (1921) Die Orchideen von Java. Sechster Nachtrag. Bulletin du Jardin botanique de Buitenzorg ser. 3, 3: 227 - 333.","Holttum, R. E. (1964) A Revised Flora of Malaya, volume I, Orchids of Malaya (3 rd ed.). Government Printing Office, Singapore, 759 pp.","Comber, J. B. (1990) Orchids of Java. The Bentham-Moxon Trust, The Royal Botanic Gardens, Kew, England, 407 pp.","Comber, J. B. (2001) Orchids of Sumatra. The Royal Botanic Gardens, Kew, England, 1026 pp.","Wood, J. J., Beaman, T. E., Lamb, A., Chew, C. & Beaman, J. H. (2011) The Orchids of Mount Kinabalu 2. Natural History Publications (Borneo), Kota Kinabalu, 730 pp.","Hooker, J. D. (1890) Flora of British India, Vol. VI, Orchidaceae to Cyperaceae. L. Reeve & Co., London, 792 pp.","Ridley, H. N. (1896) The Orchidaceae and Apostasiaceae of the Malay Peninsula. Journal of the Linnean Society 32: 213 - 416.","Muller Argoviensis, J. (1866) Baccaurea. In: De Candolle, A. Prodromus Systematis Naturalis Regni Vegetabilis 15 (2): 456 - 466.","Reichenbach, H. G. (1874) Enumeration of the orchids collected by the Rev. E. C. Parish in the neighbourhood of Moulmein, with descriptions of the new species. Transactions of the Linnean Society of London, 2 nd series: Botany 30 (1): 133 - 155.","Blume, C. L. (1825) Bijdragen tot de Flora van Nederlandsch Indie. Lands Drukkerij, Batavia, 636 pp.","Yam, T. W. (2013) Native orchids of Singapore: Diversity, Identification and Conservation. National Parks Board, Singapore.","Ong, P. T., O'Byrne, P., Yong, W. S. Y. & Saw, L. G. (2011) Wild Orchids of Peninsular Malaysia. Forest Research Institute Malaysia (FRIM) & Ministry of Natural Resources and Environment Malaysia, Kepong, Malaysia, 196 pp.","Seidenfaden, G. & Wood, J. J. (1992) The Orchids of Peninsular Malaysia and Singapore. Olsen & Olsen, Fredensborg."]}

5. Thrixspermum flammeum Toolmal, Schuit. & Culham, spec. nov. (Figs. 17–19). Type:— THAILAND. Eastern Thailand, Chaiyaphum Province, Phu Khieo Wildlife Sanctuary, Thung Kamang, 07 December 2020, N . Toolmal, B. Buaphong & K. Putaha 07122003 (holotype: TTM-Spirit; isotypes: BKF, QBG). Thrixspermum centipeda auct. non Lour.: Seidenfaden (1988: 152); Xu et al. (2010: 443); Gao & Liu (2014: 1081); Jin et al. (2019: 213). Thrixspermum flammeum is distinguished from T. centipeda by the shorter, patent stem (rarely scandent) 3.5–14(38) cm long (vs. scandent stem 30–50 cm long), the longer peduncles 4.5–14 cm (vs. peduncles 1–3 cm), the orangish flowers, 6 cm across (vs. pale creamy yellow flowers, 4–5 cm across), the longer tepals 4.2–5.3 cm long (vs. tepals 2.2–3.0 cm long), the shorter spur 4–5 mm long, covered with orangish hairs inside (vs. spur 7–8 mm long, covered with white hairs inside), the longer lateral lobes 9 mm long (vs. lateral lobes 2 mm long), the larger mid-lobe 4 mm wide (vs. mid-lobe 2.5 mm wide), the larger callus 2.5 × 2.5 mm, pubescent, apex slightly bilobed to truncate (vs. callus 1.5 × 1.5 mm, glabrous, apex obtuse). Epiphytic herb. Stems patent, rarely scandent, 3.5–14(38) cm long, with 5–11(30) internodes, cylindrical, slightly laterally compressed, curved upwards from the middle, covered with the leaf sheaths, 5–18-leaved; internodes 4–20 × 1.5–9.0 mm. Roots cylindrical, thick, elongate, 14 cm to at least 70 cm long, 0.5–3.1 mm diam., arising from the basal part of the stem and from nodes at the lowest leaf, not or sparsely branching. Leaves green, sometimes spotted or suffused with purplish red, patent, elliptic to oblong, 5–18 × 1.2–3.3 cm, sessile, slightly narrowed towards the base, leaves on the same side of the stem 2–3 cm apart, dorsiventrally flattened, apex unequally bilobed with obtuse lobes, with a small mucro in the middle, thick, rigid, fleshy, coriaceous, the midrib distinct on the abaxial side; leaf sheaths green, sometime spotted or suffused with purplish red, slightly bilaterally compressed, longer than the stem internodes. Inflorescences two to eight per plant, patent, racemose, 7–22 cm long, long pedunculate, arising from the nodes at the opposite side of the leaves and below the roots, green with purplish red spots; peduncle slender, slightly upwards curved from the middle, 4.5–14 cm long, 1.3–6.0 mm diam., with 3 internodes, the basal internode fairly short, stout, 1–3 cm long, 0.5–2 mm in diam., the middle internode longer, 4–8 cm long, 1.6–2.3 mm diam., the terminal internode strongly bilaterally compressed distally, 2–4 cm long, broadening to 6 mm diam. just below rachis; peduncle scales 3, green with purplish red spots, ovate to broadly triangular, incurved, concave, thickened, slightly boat-shaped, clasping the peduncle, 5.0–7.4 × 2.0– 2.2 mm, apex acuminate, keeled; rachis 1.5–12.0 cm long, depending on the age of the inflorescence, 6–29-flowered, with one or two flowers open at a time, strongly bilaterally flattened, with distichous, persistent floral bracts, 1–8 mm apart, 0.7–1.2 cm wide across the floral bracts. Floral bracts green to yellowish, sometimes with purplish red spots, bilaterally flattened, ovate to broadly triangular, incurved, concave, thickened, slightly boat-shaped, clasping the rachis, 5–9 × 2.7–3.2 mm, apex acute, keeled. Pedicel-with-ovary yellowish green, cylindrical, 6-grooved, 8–11 mm long, c. 1.5 mm diam. Flowers non-resupinate, opening widely, lasting one to two days, mildly sweet-scented, membranaceous, 6 [5] cm across; tepals orange, yellowish at the base, lip pale yellow, with reddish brown spots on both surfaces of the lip between the lateral lobes, the midlobe and apical part of the lateral lobes white, the spur with 1 mm diam. reddish brown rounded warts on the back wall which shine through on the outside, the callus creamy white tinged reddish brown abaxially, the anther, column, column-foot, stipe and viscidium creamy white. Sepals incurved at the base. Dorsal sepal linear, 48–53 [30] × 3.5–4.0 [3.0] mm, slightly tapering towards the apex, slightly concave, somewhat twisted near the base, apex acuminate, glabrous, 5-nerved. Lateral sepals linear, obliquely subhorizontal, 48–53 [30] × 4.0–4.5 [5.0] mm, slightly tapering towards the apex, rather concave, somewhat twisted and expanded near base, apex acuminate, glabrous, 5-nerved. Petals similar to sepals, slightly smaller, obliquely, 42–50 [26] × 2–3 [2] mm, apex acuminate, glabrous, 5 [3]-nerved. Lip oblong to cylindrical in outline, 3-lobed, c. 15 [12] × 4–6 [5] mm in natural position, 12 [10] mm wide when spread, with a broad, sac-like spur at the base; spur broadly conical, 4–5 [3] × 4–5 [5] mm, apex 2-lobed with obtuse lobes (0.5 × 2.5 mm), on the back wall densely covered with long orangish hairs (0.5 mm long), turning to white hairs at the base of the callus; lateral lobes narrowly triangular to slightly ovate, falcate, 9 [8] × 3–4 [3] mm, free part 2 [1] mm long, erect, curving outwards, short pubescent on both surfaces, apex acute to slightly obtuse; mid-lobe narrowly triangular, 5–7 [4] × 4 [4] mm, entirely concave (4 [3] mm long), sparsely pubescent on both surfaces, slightly convex and pubescent in apical 1.5 [1] mm, 2 [3] mm thick, more or less evenly thick from base to apex, apex obtuse; lip between the lateral lobes sparsely pubescent on both surfaces, with a tongue-shaped callus a little below the mid-lobe, callus 2.5 mm long, 2.5 mm diam., sparsely pubescent, apex slightly bilobed to truncate, decurved. Column cylindrical, short, stout, 2–3 × 2.5–3.0 mm, laterally winged; column-foot short, broad, 3–4 × 3–4 mm. Anther suborbicular in outline, glabrous, 2 × 2 mm, the median with a longitudinal ridge. Pollinia in 2 pairs, those in a pair unequal, lanceolate-ellipsoid, curved; the larger 1.7 × 0.7 mm; the smaller, 1.5 × 0.5 mm; stipe broadly ovate-elliptic, 0.5× 0.5 mm, concave along the median, slightly translucent; viscidium transverse-linear, 0.2 × 0.6 mm, bent into a crescent shape, slightly translucent. Fruit green, cylindrical, 5–9 cm long, 6.0– 8.5 mm diam., with 6 longitudinal ridges. Described from living plants and flowers, and spirit material. Measurements between square brackets refer to Kew cult. 2017-20 from Mt. Bokor, Cambodia. Distribution:— CHINA. Yunnan. THAILAND. Northern: Mae Hong Son Province (Huai Hi, Pang Tong Palace, Boo Salee), Chiang Mai Province (Fang, Doi Pha Hom Pok National Park, Wat Chan, Doi Pha Dam, Doi Ngao, Doi Suthep-Pui National Park), Lampang Province (Khun Tan National Park), Tak Province (Umphang), Uttaradit Province (Phumiang–Phuthong Wildlife Sanctuary), Phitsanulok Province (Phu Hin Rong Kla National Park); North-Eastern: Phetchabun Province (Nam Nao National Park, Thung Salaeng Luang National Park, Loei Province (Phu Kradueng National Park, Phu Rua National Park, Phu Luang Wildlife Sanctuary); Eastern: Chaiyaphum Province (Phu Khiao Wildlife Sanctuary, Nam Prom), Nakhon Ratchasima Province (Khao Yai National Park). LAOS. Houaphanh Province (Nong Hua Pa Noi Village, Ban Na Pe), Champasak Province (near Tad Fane Waterfall). CAMBODIA. Kampot (Mt. Bokor). VIETNAM. Dak Lak (Chu Yang Sin National Park), Thua Thien Hue (Ta Lo Village), Dak Nong (Nam Nung Protected Area), Gia La-Kon Tum (Mang Den) (Fig. 28). Etymology:—From the Latin flammeus, flame-coloured, referring to the orange tepals. Phenology:—Flowering in April, May, June, July, September and October (in natural habitat); February, March, April, October, November and December (in cultivation). Flowering is probably intermittent throughout the year, as in most species of Thrixspermum. Habitat and ecology:—Epiphyte in deciduous dipterocarp forest, dry and wet evergreen forest, lower montane rain forest, lower montane coniferous forest, lower montane scrub and upper montane rain forest and in coffee plantations, at 500–1,700 m elevation, locally common, growing on trunks or twigs of trees, such as Pinus kesiya Royle ex Gordon (1840: 8) (Pinaceae) in coniferous forest in Thailand, in exposed positions at about 1–5 meters above the ground. Conservation status:— Thrixspermum flammeum is a widespread species, distributed from southern China to northern Thailand, Laos, Cambodia and Vietnam, with an Extent of occurrence (EOO) of 761,461.557 km 2 and an Area of occupancy (AOO) of 124.000 km 2. It is locally common with a large number of individuals. It is, therefore, assigned the conservation status of Least Concern (LC) according to IUCN criteria. Vernacular (Thailand):—Maeng Mum Som (แมงมุมส̊ม), Ta Khap Som (ตะขาบส̊ม). Additional specimens examined:— CHINA. Yunnan, A. Henry 12081 (K s.n.!). THAILAND. Northern: Mae Hong Son Province, Mueang District, Huai Hi, Pasayu Pripasertying 115, 21 April 1999 (BK s.n.!), Pang Tong Palace, P. Suksathan 4290, 05 July 2007 (QBG 30670!), Boo Salee, S. Pumicong & S. Watthana 245, 03 May 2006 (QBG 27976!), Chiang Mai Province, Fang District, Seidenfaden & Smitinand GT 2100 (C 8342!, Seidenfaden 1988: 152 as T. centipeda), Doi Pha Hom Pok National Park, S. Damapong 25, 18 May 2006 (QBG 37287!), Galyani Vadhana District, Wat Chan, Ban Den, M. Norsaengsri 10954, 29 April 2014 (QBG 72841!), Doi Pha Dam between Hang Dong and Bo Luang, Kai Larsen et al. 2135, 05 July 1968 (AAU s.n.!, Seidenfaden 1988: 152 as T. centipeda), Mae Chaem, Doi Ngao, A.F.G. Kerr s.n., 12 May 1921 (K s.n.!, Seidenfaden 1988: 152 as T. centipeda), Doi Suthep-Pui National Park, A.F.G. Kerr 98, 20 May 1912 (K s.n.!, AMES s.n.!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 2645, July 1958 (C 8297!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 2394, May 1958 (C 8312!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 2943, October 1958 (C 8313!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 2388, May 1958 (C 8326!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 2822, July 1958 (C 8327!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 2228, July 1958 (C 8297!, Seidenfaden 1988: 152 as T. centipeda), Lampang Province, Khun Tan National Park, Put 150, 12 May 1933 (BK s.n.!, BKF 15673!, Seidenfaden 1988: 152 as T. centipeda), Tak Province, Umphang District, S. Suddee et al. 5074, 05 April 2016 (BKF s.n.!), Uttaradit Province, Nam Pat District, Phumiang–Phuthong Wildlife Sanctuary, Seidenfaden & Smitinand GT 5432, 22 May 1964 (C 8332!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 5483, 30 April 1964 (C 8341!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 5796, 30 April 1964 (C 8341!, Seidenfaden 1988: 152 as T. centipeda), Romklao Botanical Garden 0280/2554, 11 July 2011 (QBG 59889!), Phitsanulok Province, Nakhon Thai District, Phu Hin Rong Kla National Park, S. Pumicong 229, 26 July 2006 (QBG 28803!); North-Eastern: Phetchabun Province, Nam Nao District, Nam Nao National Park, T. Smitinand 558, 24 April 1951 (BKF 4944!, P. 00324331!, Seidenfaden 1988: 152 as T. centipeda, C 8348!, P 00324331!), Seidenfaden & Smitinand GT 8714, 20 March 1980 (C 8345!, 8347!, Seidenfaden 1988: 152 as T. centipeda), Nong Mae Na District, Thung Salaeng Luang National Park, Huay Khek, Seidenfaden & Smitinand GT 5580, 25 February 1964 (C 5580!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 5564 (C 5583!, Seidenfaden 1988: 152 as T. centipeda), O. Phueakkhlai et al. 22, 18 May 2007, (BKF 186359!), Loei Province, Na Haew, Phusansai, Tad Hueang Waterfall, C. Maknoi 837, 16 May 2016 (QBG 27651!). Phu Kradueng National Park, Seidenfaden & Smitinand GT 747, April 1957 (C 8306!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 3748 (C 8307!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 3770, April 1957 (C 8308!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 3060, October 1958 (C 8316!, 8323!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 3062 (C s.n.!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 3063, April 1959 (C 8331!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 3764 (C s.n.!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 3765 (C 8299!, Seidenfaden 1988: 152 as T. centipeda), Huay Tham Yai, T.Smitinand 382, 12 May 1951 (BKF 4959!, Seidenfaden 1988: 152 as T. centipeda), Tham Saw, T. Smitinand 404, (BKF s.n.!, Seidenfaden 1988: 152 as T. centipeda), Thum Saw Nuea waterfall, S. Suddee et al. 4460, 07 July 2013 (BKF s.n.!), Lan Pra Kaew, P. Jongsirikankha 44, 22 May 2015 (BKF 194058!), Phu Rua District, Phu Rua National Park, Camp Site 2, N. Toolmal et al. 09122001, 09 December 2020 (TTM 0006390!), Phu Luang District, Phu Luang Wildlife Sanctuary, BKF 0135 (C 8330!, Seidenfaden 1988: 152 as T. centipeda), Seidenfaden & Smitinand GT 8561 (C 8333!, Seidenfaden 1988: 152 as T. centipeda), Khok Nok Kra Ba, N.Toolmal et al. 10122001, 10 December 2020 (TTM 0006391!); Eastern: Chaiyaphum Province, Khon San District, Phu Khieo Wildlife Sanctuary, Seidenfaden & Smitinand GT 8120, July 1973 (C 8325!, Seidenfaden 1988: 152 as T. centipeda), Thung Kamang, N.Toolmal et al. 07122003, 07 December 2020 (TTM 0006386!), Nam Prom, Seidenfaden & Smitinand GT 8794 (C 8336!, Seidenfaden 1988: 152 as T. centipeda), Nakhon Ratchasima, Khao Yai National Park, Khao Khieo, Seidenfaden & Smitinand GT 5878b (C 8320!), J.Y. Vidal & Niyomdham 6373, 08 June 1979 (AAU s.n.!, P 00509691!, P 00324332!, Seidenfaden 1988: 152 as T. centipeda), Ch. Charoenphol, Kai Larsen & E. Warncke 4230, 29 October 1970 (AAU s.n.!, P 00324330!), J.B. Comber 1645, 08 June 1986 (K s.n.!). LAOS. Houaphanh Province, Xon District, Nong Hua Pa Noi Village, N.T. Hiep et al. LA-VN 1267, 11 April 2015 (LE 01076325!), Ban Na Pe, C.J. Spire 485, 19 May 1903 (P 00324333!); Champasak Province, near Tad Fane Waterfall (photos by A. Schuiteman!). CAMBODIA. Kampot Province, Mt. Bokor, Kew cult. 2017-20 (photos by A. Schuiteman!), Angkor, C. Thorel s.n. (P 00324334!, P 00324335!, P 00324336!), Mont de Pursat, A. Godefroy 444, 10 June 1875 (P 00324337!, P 00324338!, P 00324339!). VIETNAM. Dak Lak Province, N.V. Canh s.n., 29 May 2010 (LE 01122217!), Lak and Krong Bong Districts, Chu Yang Sin National Park, Chu Yang Sin Mountain, Nuraliev s.n., 11 April 2012 (LE 01122222!, 01122223!), Thua Thien Hue Province, A Luoi District, Hong Van Municipality, Ta Lo Village, L. Averyanov et al. HAL 7640, 29 April 2005 (LE 01076332!), Dak Nong Province, Dak Song District, Nam Nung Protected Area, L. Averyanov et al. AL 1182, 25 October 2019 (LE 01066593!), Gia La-Kon Tum Province, Kon Plong District, Mang Den, L. Averyanov et al. LX-VN 2293, 28 May 1985 (LE 01076419!). Taxonomic notes:— Thrixspermum flammeum is another species that has been confused with T. centipeda, from which it differs in the characters listed in the diagnosis. It is in general a shorter-stemmed plant with distinctly longer (4.5–14 cm long) peduncles, whereas the true T. centipeda tends to have long climbing stems and short (1–3 cm long) peduncles. Characteristic for T. flammeum is that the sepals and petals are usually curved such that the apical parts are almost parallel and pointing downwards., Published as part of Toolmal, Nopparut, Suddee, Somran, Culham, Alastair, Utteridge, Timothy M. A. & Schuiteman, André, 2023, Taxonomic notes on Thrixspermum (Orchidaceae: Aeridinae), with five new species from Thailand, pp. 223-262 in Phytotaxa 601 (3) on pages 248-253, DOI: 10.11646/phytotaxa.601.3.3, http://zenodo.org/record/8141764, {"references":["Seidenfaden, G. (1988) Orchid genera in Thailand XIV. Fifty-nine vandoid genera. Opera Botanica 95: 1 - 398.","Xu, Z., Jaing, H., Ye, D. & Liu, E. (2010) The Wild Orchids in Yunnan. Yunnan Publishing Group Cooperation, Yunnan Science & Technology Press, Beijing, 500 pp.","Gao, J. & Liu, Q. (2014) Orchids of Xishuangbanna; Diversity and Conservation. China Forestry Publishing, Beijing, 237 pp.","Jin, X., Li, J. & Ye, D. (2019) Atlas of Native Orchids in China. Vol. 2. Henan Science and Technology Publishing House, China, 1257 pp.","Gordon, G. (1840) Report on the new species of hardy trees and shrubs. Gardener's Magazine and Register of Rural and Domestic Improvement, n. s., 6: 1 - 10."]}