Disperis Swartz (1800: 218)

Averyanov, Leonid V., Nguyen, Van Canh, Le, Tuan Anh, Vuong, Truong Ba, Nuraliev, Maxim S., Maisak, Tatiana V., Yudova, Daria A., Nguyen, Cuong Huu & Nong, Duy Van, 2024, New orchids in the flora of Vietnam IX (Orchidaceae: Orchidoideae, tribes Cranichideae and Orchideae), Phytotaxa 664 (4), pp. 229-248 : 234-235

Disperis Swartz (1800: 218)

Disperis neilgherrensis Wight (1851: 15 , tab. 1719), Hooker (1890: 169), Fischer (1928: 1478), Bose & Bhattacharjee (1980: 244), Jain & Mehrotra (1984: 52), Joseph (1987: 37, Pl. 16), Bose et al. (1999: 224, drawing), Kurzweil (2005: 145, fig. 1), Kurzweil & Manning (2005: 174) , Chen et al. (2009a: 188, photo, 2009b: 165, fig. 223 (1, 2), 224), Xu et al. (2010: 120, photo), Pedersen et al. (2011a: 56, fig. 28), Gao et al. (2013: 139, photo), Lin & Wang (2014: 370, figs. A–C), Lin et al. (2016: 95), Zhou et al. (2016: 53), Kang et al. (2019: 98, fig. 1C, D), Aung et al. (2020: 83), Ormerod et al. (2021: 126) , Jin et al. (2023: 117, figs. 1, 2).

( Fig. 4 )

Lectotype (designated by Kurzweil (2005: 145):— INDIA . [Tamil Nadu State: Coimbatore, Nilgiri Hills ,] R. Wight 3018 ( K K000827269 photo! https://data.kew.org/records/occurrences/1fe176f5-0413-4d47-a8ff-ee4ab615b72d, K000827270 ; isolectotypes: C, GH 00098943 photo! https://kiki.huh.harvard.edu/databases/specimen_search.php?mode=details&id=46057, GOET GOET008394 photo!, LE LE01254354 ! https://en.herbariumle.ru/?t=occ&id=216684, M M0225994 photo!, P P00362244 photo! http://coldb. mnhn.fr/catalognumber/mnhn/p/p00362244, P00362245 photo! http://coldb.mnhn.fr/catalognumber/mnhn/p/p00362245, S S07- 1697 photo! https://herbarium.nrm.se/specimens/ S07-1697 , W, ZT ZT-00014369 photo!). Citation of protologue: —“Neilgherries in woods on large mossy stones, and moist loose vegetable soil”.

= D. javanica Smith (1914: 19) , Comber (1990: 71). Type: — INDONESIA. Java, Lawoe, near Djogorogo, ca. 900 m, February 1913, C.A. Backer 6765 (BO fide Kurzweil 2005).

= D. siamensis Rolfe ex Downie (1925: 422) , Seidenfaden & Smitinand (1959: 53), Seidenfaden (1969: 101, fig. 1, 1977: 139, fig. 89), Chen & Tsi (1998: 41), Su (2000: 857), Yokota (2016: 225). Type: — THAILAND. [Chiang Mai Province:] Doi Suthep, deciduous jungle, flowers white with violet markings, 2200–3000 ft [660–900 m], 27 August 1911, A.F.G. Kerr 1987 (lectotype, designated by Seidenfaden (1969: 101): K K000827015 photo! https://data.kew.org/records/occurrences/a1d5f431-01ab-4de7-a202-bbcb4bedf560; isolectotype: C C10016216 photo!).

= D. lantauensis Hu (1972: 17) , Chen & Tsi (1998: 41), Chen et al. (1999: 194, photo, 2007: 194, photo, as “ nantauensis ”), Hu & Kong (2011: 306). Type: — CHINA. Hong Kong: Lantau Island, Sunset Peak, 900 m, tiny plants buried in grasses, 30 July 1970, S.Y. Hu 10812 (holotype possibly A, indicated as “AA”).

Habitat and phenology in Vietnam: —Lowland evergreen broad-leaved forests at elevation of about 700 m a.s.l. Flowers in July–August.

Distribution: — Vietnam (Quang Tri Province: Huong Hoa District). India , Sri Lanka, Myanmar, Japan (the Ryukyu Islands), China (Yunnan, Hong Kong, Taiwan), Thailand, the Philippines, Java, Flores, the Maluku Islands, the Caroline Islands, New Guinea.

Conservation status in Vietnam: —Comprehensive conservation assessment of Disperis neilgherrensis is complicated by the scarcity of information about its single known Vietnamese population. We estimate the national conservation status of the species as Critically Endangered (CR) in accordance with the following formal IUCN criteria: B1a,b(i-v)+B2a,d(i-v), D1. Jin et al. (2023) assessed the status of this species as Near Threatened (NT) but have not provided any details or reasons for their decision.

Notes: —The protologue of Disperis siamensis ( Downie 1925) cites a single gathering, Kerr 1987, without indication of a place of its deposition. Seidenfaden (1969) cited this gathering as “ Kerr 1987 C!, K, type ”. As follows from the other examples from the Seidenfaden’s paper (e.g. pp. 125, 127, 138), he put the word “ type ” directly after the acronym of the herbarium of the type deposition, designating a specimen in a particular herbarium (rather than the entire gathering) as a type. Seidenfaden’s study therefore fulfills the conditions of lectotypification (Art. 7.11 of ICN, Turland et al. 2018). Among the K collections, we have found a single specimen belonging to this gathering, K000827015.

Disperis neilgherrensis is reported here as a new record for the flora of Vietnam, representing the first record of the genus Disperis in the country. The discovery of this species in Vietnam was highly expectable, as the country lies within the outlines of the global area of the species occurrence. Although about a dozen of species of Disperis have been described from Asia and Australasia, Kurzweil (2005) demonstrated that they actually represent a single variable species. The rest of the species diversity of the genus is confined to the African region. The collection from Vietnam reported here is morphologically very close to the other known records from mainland Southeast Asia illustrated, for instance, by Pedersen et al. (2011a) and Jin et al. (2023).

Studied specimen:— VIETNAM. Quang Tri Province: Huong Hoa District, Huong Phung Commune, Chenh Venh Stream, 16°46’44.1’’N 106°35’02.0’’E, ca. 700 m a.s.l., 6 August 2023, Tuan Anh Le, LTA 993 (LE LE01253749 https://en.herbariumle.ru/?t=occ&id=211949, photos LE LE01124302 https://en.herbariumle.ru/?t=occ&id=186707).

Figures

FIGURE 4. Disperis neilgherrensis. A. Flowering plant in natural habitat. B. Flattened flowering plants. C. Leaves, view from different sides. D. Adaxial leaf surface. E, F. Tubers. G, H. Tuber, cross section. I. Flower buds, view from different sides. J. Peduncle, floral bract and flower, side view. K. Flower, front views. L. Flower, side view. M. Flowers, front, half-side and rear views. N. Column, front and halfside views. O. Ripening fruits, side view. P. Ripening fruit, cross section. Photos by Tuan Anh Le from living plant prior to the preparation of the voucher herbarium specimen Tuan Anh Le, LTA 993. Photo correction and design by L. Averyanov and T. Maisak.