Dendrobium thinhii Aver., sp. nov.
Type :—VIETNAM. Kon Tum province: Ngoc Linh Mountains, mountain evergreen forest at elevation about 1700 m a.s.l., 28 April 2015, D.P. Thinh, L.Averyanov, T.Maisak, N.V.Duy, AL 34 (holotype, LE!).
Etymology: Species epithet refers to the name of its discoverer, orchid enthusiast—Mr. Do Phu Thinh.
Habitat, phenology and conservation status:—Miniature branch and trunk epiphyte. Primary submontane and montane evergreen, broad-leaved forests on granite. 1700 m. Fl. April-May. Very rare. Estimated IUCN Red List status—DD.
Distribution:—Vietnam: Kon Tum province (Ngoc Linh Mountains). Endemic.
Notes:—This new species belongs to distinct group of Dendrobium species historically known as a section Breviflores (Hooker 1890: 711), but it is totally different from all known species of this section, as well as from other its congeners. Snow-like pseudopollen deposits on the lip, large glabrous callus on the disc and other specific lip structures are the most obvious individual features of this remarkable novelty species. Flowers of this plant have a very pleasant, extremely strong fragrance when fresh and surprisingly remaining even in completely dried herbarium samples. Formation of pseudopollen in flowers of this species is evolutionarily expressed to a greater extent than in any other orchid species in Indochina. It is remarkable that this species grows in the region of Dendrobium farinatum Schildhauer & Schraut (2004: 374) and D. unicum Seidenfaden (1970: 332), two other local endemics of eastern Indochina forming pseudopollen. The formation of pseudopollen is a rather rare phenomenon and coexistence of these three species may indicate regional and specific traits of pollination evolution in their overlapping distribution area.
Sarcoglyphis tichii Aver., sp. nov.
Type:—VIETNAM. Lam Dong province: Duc Trong district, about 30 km to the east of Dalat City, 24 April 2015, N.P.Tam, AL 12 (holotype, LE!). Figs 2, 5A-D.
Etymology:—Species name refers to the name of eminent botanist, orchid expert and lecturer at the Ho Chi Minh City University of Science—Mr. Nguyen Thien Tich.
Habitat, phenology and conservation status:—Miniature branch epiphyte. Primary and mature secondary broad-leaved evergreen humid submontane forests on granite. 1,000-1,200 m. Fl. March-April. Very rare. Estimated IUCN Red List status—DD.
Distribution:—Vietnam: Lam Dong province (Duc Trong district). Endemic.
Notes:—The genus Sarcoglyphis includes 14 species distributed in tropical zones of mainland Asia and Sunda Isles. The newly discovered species differs from all its known congeners in having smaller, half-sized flowers and peculiar concavities on the side lobes appearing inside as a prominent broadly conical protuberances. This species appears fairly morphologically isolated and has a slight superficial resemblance to the relatively small-flowering, S. thailandica Seidenfaden (1988: 127), but which distinctly differs in having a very long rostellum (almost as long as column), a very long beak of the operculum, a narrow conical median lip lobe and a short septum inside the spur. The rostellum protuberance raised up at the front of the clinandrium observed in most species of the genus is reduced in the new taxa into a small ovoid callus. This feature provides similarity with some species of Cleisostoma Blume (1825: 362).
Taeniophyllumphitamii Aver., sp. nov.
Etymology:—Species is named after its discoverer and orchid enthusiast—Mr. Nguyen Phi Tam.
Habitat, phenology and conservation status:—Miniature canopy and branch epiphyte. Submontane broadleaved evergreen forests on granite, often found on steep mountain slopes. 1200-1300 m. Fl. March-May. Very rare. Estimated IUCN Red List status—DD.
Distribution:—Vietnam: Lam Dong province (Dalat City area). Endemic.
Notes:—Species may be close to T. rubrum Ridley (1896: 364) known from Kalimantan and Malacca Peninsula, having similar reddish inflorescence, floral bracts and flowers. Meanwhile, the new taxon differs in having much smaller, bright red, hardly opening flowers, many flowered inflorescences, a densely glandular verruculose rachis, floral bract and ovary, as well as containing fleshy, keeled, acute sepals and petals. Discovered species is a lone red- flowering member of the genus in mainland Asia. It was found in association with Chiloschista exuperi (Guillaumin 1957: 346) Garay (1972: 166), another endemic of southern Indochina.
Trichoglottis canhii Aver., sp. nov.
Type :—VIETNAM. Dak Lak province: Ea H’leo district, Ea Wy municipality, epiphyte on relictual trees in remnants of dry Dipterocarp forest, 500 m a.s.l., around point 13°14’39’N 108°08’38’’E, 27 April 2015, N.V.Canh, L.Averyanov, T.Maisak, AL 32 (holotype, LE!).
Etymology:—Species is named after the outstanding Vietnamese orchid enthusiast and excellent wild-orchid grower—Mr. Nguyen Van Canh.
Habitat, phenology and conservation status:—Miniature branch epiphyte. Lowland dry open semideciduous and deciduous Dipterocarp forests and woodlands, usually on ferralitic soils. 500 m. Fl. March-May. Very rare. Estimated IUCN Red List status—DD.
Distribution:—Vietnam: Dak Lak province (Ea H’leo and Ea Sup districts). Endemic.
Studied specimens (paratypes):—VIETNAM. Dak Lak province: Ea Sup district, Yok Don national park, dry Dipterocarp forest, 2015, Hiep & N.Phong, AL 9 (LE!). Ea H’leo district, Ea Wy municipality, epiphyte on relictual trees in remnants of dry Dipterocarp forest at elev. about 500 m a.s.l., around point 13°14’39’N 108°08’38’’E, 26 April 2015, N.V.Canh, L.Averyanov, T.Maisak, AL 15a (LE!).
Notes:—The new species is somewhat related to relation to Trichoglottis lorata (Rolfe ex Downie 1925: 407) Schuiteman (2007: 62) (Staurochilus loratus (Rolfe ex Downie 1925: 407) Seidenfaden 1988: 95) and Trichoglottis ramosa (Lindley 1833-1840: 224) Senghas (1988: 1315) (Staurochilus ramosus (Lindley 1833: 224) (Seidenfaden 1988: 95), but differs distinctly in having short, always simple, dense inflorescences, smaller flowers, much shorter and broad spur and a dissected back-wall lamella. The plant discovered also resembles Trichoglottis triflora (Guillaumin 1956: 239) Garay & Seidenfaden (Garay 1972: 209) on its miniature habit, short inflorescences and small flowers. In this connection, it may represent an intermediate phylogenetic “link” between the above mentioned species strongly supporting the idea of the merging of the genera Trichoglottis Blume (1825: 359) and Staurochilus Ridley ex Pfitzer in Engler & Prantl (1900: 16) (Schuiteman & Vogel, 2007).
Full text of this publication is on Phytotaxa 238 (2): 136-148 with authors incudes
Averyanov (Komarov Botanical Institute, Russian Academy of Science, St. Petersburg, Prof. Popov Str. 2, Russia) và cộng sự gồm Nong Van Duy, Tran Thai Vinh, Quach Van Hoi and Vu Kim Cong (Tay Nguyen Institute for Scientific Research, Vietnam Academy of Science and Technology, 116 Xo Viet Nghe Tinh St., Da Lat City, Lam Dong, Vietnam)