taxonID	type	description	language	source
038CE12F1512FFB5AB9FD535FE5CFEA7.taxon	description	(Figs. 1 A, B)	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1512FFB5AB9FD535FE5CFEA7.taxon	materials_examined	Type: — CHINA. Yunnan: Malipo County, on trees in forest, alt. 1000 m, 27 Aug. 2008, Z. J. Liu 4137 (holotype – NOCC).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1512FFB5AB9FD535FE5CFEA7.taxon	biology_ecology	Habitat, phenology and conservation status: — Epiphyte. Broad-leaved evergreen submontane forests on karstic limestone at elevation about 1000 m a. s. l. Fl. October – November. Very rare. Suggested IUCN Red List status – EN.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1512FFB5AB9FD535FE5CFEA7.taxon	distribution	Distribution: — Northern Vietnam (Ha Giang and Lai Chau provinces), SE China (SE Yunnan).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1512FFB5AB9FD535FE5CFEA7.taxon	discussion	Note: — According to available data, this very rare species has been found only in three documented locations in SE Yunnan (China) and in two provinces of N Vietnam (Ha Giang and Lai Chau) geographically forming triangle with approximate sides 200 × 200 × 40 km and lying along the Vietnamese – Chinese border. In terms of the IUCN Red List, the species has an estimated area of occurrence (EOO) less than 4000 km 2 and area of occupancy (AOO) is 12 km 2. There is continuing decline in the quality of habitat due to intensive deforestation and agricultural exploration throughout occurrence area. The wide loss of habitats and commercial collecting are strong factors affected the species’ population and bringing the number of mature individuals down. Hence, the species is assessed as Endangered – EN B 2 ab (iii, v) according to formal IUCN criteria (IUCN 2019).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1512FFB5AB9FD535FE5CFEA7.taxon	materials_examined	Studied specimens: — VIETNAM, Lai Chau Province, broad-leaved limestone forest, plant collected by local collector for Mr. Loc Bao Sang, who cultivated plant in his private garden in Lam Dong, Di Linh Town, 26 October 2019, L. Averyanov, Nguyen Van Canh, T. Maisak, AL 1187 (LE 01066616 http: // en. herbariumle. ru /? t = occ & id = 12384, LE 01088196 https: // en. herbariumle. ru /? t = occ & id = 43730). VIETNAM, the plant was purchased mixed with Renanthera vietnamensis, originating from Ha Giang Province, Quang Ba District and cultivated in Dalat Town, Lam Dong Province by Mr. Nguyen Phi Tam s. n., photo of 08.11.2021, AL 1295 (LE 01123004 https: // en. herbariumle. ru /? t = occ & id = 110370).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1511FFB5AB9FD127FF75FAFA.taxon	description	(Figs. 1 C, D)	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1511FFB5AB9FD127FF75FAFA.taxon	materials_examined	Type: — VIETNAM. S Vietnam, Dak Nong Province, Krong No District, Nam Nung Commune, shrubs along streams in evergreen forest at elevation 800 – 900 m a. s. l., flowers in April – May, 13 April 2018, Nguyen Van Canh, Nguyen Hoang Tuan, s. n. (holotype LE 01042185 https: // en. herbariumle. ru /? t = occ & id = 332, photos LE 01123088 https: // en. herbariumle. ru /? t = occ & id = 134258).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1511FFB5AB9FD127FF75FAFA.taxon	etymology	Etymology: — Variety name refers small size of its flowers.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1511FFB5AB9FD127FF75FAFA.taxon	description	Description: — Herb leafless, miniature, monopodial, with stem 3 – 4 mm long and many dense, flexuose, tufted, gray green roots 4 – 10 cm long. Inflorescence hairy, 2 – 2.5 cm long; scape 1.2 – 1.4 cm long, with 2 – 5 distant sterile triangular scarious bracts. Rachis 8 – 10 mm long with (2) 3 (4) flowers; floral bracts triangular, acute, scarious 1.5 – 2 mm long. Pedicel and ovary 1.8 – 2.2 mm long. Flowers yellowish, tepals speckled with brown, widely opening, 5.5 – 6 mm across; median sepal elliptic ovate, (3.4) 3.5 (3.6) mm long, (2.6) 2.7 (2.8) mm wide; lateral sepals distinctly smaller, obliquely broadly ovate, (2.1) 2.2 (2.3) mm long, (1.9) 2 (2.1) mm wide; petals triangular broadly ovate, (2.7) 2.8 (2.9) mm long and wide; lip 3 - lobed, 1.5 – 1.6 mm long with erect obovate side-lobes (1.3) 1.4 (1.5) mm long. Fruit unknown. Habitat, phenology and conservation status: — Epiphyte. Broad-leaved evergreen submontane forests and shrubs at elevations of 800 – 900 m a. s. l. Fl. April – May. Very rare. Suggested IUCN Red List status – DD.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1511FFB5AB9FD127FF75FAFA.taxon	distribution	Distribution: — Southern Vietnam (Dak Nong Province, Krong No District). Endemic. Note: — Chiloschista parishii described from Myanmar (Seidenfaden 1988) has a wide distribution in India, Nepal, Bhutan, Myanmar, China, Thailand, Laos and Vietnam. This species is very variable in floral morphology and coloration, and has relatively large flowers, commonly 8 – 12 mm across (Pearce & Cribb 2002). Such plants were observed and collected in many areas in Vietnam, however, the small flowering variety recently discovered there has not been reported before. It has very similar floral structure to the typical variety C. parishii var. parishii, but differs in all parts of the flower, which are twice smaller, namely flower 5.5 – 6 mm across (vs. flowers 8 – 12 mm across), median sepal 3.4 – 3.6 mm long (vs. median sepal 5 – 6 mm long), lateral sepals 2.1 – 2.3 mm long (vs. lateral sepals 4 – 5 mm long), petals 2.7 – 2.9 mm long (vs. 5 – 6 mm long), and lip 1.5 – 1.6 mm long with side-lobes 1.3 – 1.5 mm tall (vs. lip and side-lobes 2.5 – 3 mm long). The new variety has so far only been found in the type locality and may be regarded as a narrow endemic. However, this small and unattractive plant may have a broader distribution but has possibly been overlooked. Under these circumstances, the IUCN conservation status may be tentatively assessed as Data Deficient DD.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1511FFB5AB9FD583FE49F7AE.taxon	description	(Figs. 1 E – G)	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1511FFB5AB9FD583FE49F7AE.taxon	materials_examined	Type: — MALAYSIA. Malay Peninsula, North Perak, June 1965, cult. Penang, Lim Swee Linn sine n. (holotype K 000891272). Habitat, phenology and conservation status: — Epiphyte. Broad-leaved evergreen lowland forests. Fl. June. Very rare. Suggested IUCN Red List status – DD.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1511FFB5AB9FD583FE49F7AE.taxon	distribution	Distribution: — Vietnam. Malaysia (Malay Peninsula). Note: — The occurrence of this species in Vietnam is documented only by a series of photos made an anonymous photographer from cultivated plants in a private garden in Buon Me Thuot Town (Dak Lak Province). It is very close to the widespread C. parishii, differing primarily “ in the quite high narrow triangular side-lobes and the hairy edges of the petals ” (Seidenfaden & Wood 1992) and may be regarded as its southern allopatric race. The locality of this species in Vietnam, which is more than 1300 km distant from the locus classicus in Malacca Peninsula, needs confirmation by more collections or observations. According to available data its IUCN conservation status should be assessed as Data Deficient DD. Studied specimens: — VIETNAM, wild collected plant cultivated in private garden probably originating expectedly from northern Vietnam, anonymous photo in Nguyen Van Canh archive s. n. (LE 01088051 https: // en. herbariumle. ru /? t = occ & id = 45097).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1516FFB2AB9FD097FD8CFA4B.taxon	description	(Figs. 1 H, I, 2)	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1516FFB2AB9FD097FD8CFA4B.taxon	materials_examined	Type: — VIETNAM. S Vietnam, Soviet-Vietnamese Expedition, Province Quangnam – Danang, Da Nang, Son Tra, 09.07.1986, LX-VN 0 - 14, fl. et coll. in horto 25 11 1987, herbarium prepared by Averyanov L., 1987) – LE (holotype – LE 01059075 https: // en. herbariumle. ru /? t = occ & id = 9915, epitype – LE 01059069 https: // en. herbariumle. ru /? t = occ & id = 9909, photos – LE 01088036 https: // en. herbariumle. ru /? t = occ & id = 46070). Habitat, phenology and conservation status. Epiphyte. Broad-leaved evergreen lowland forests on granite at elevation of 50 – 400 m a. s. l. Fl. June – July. Very rare. Suggested IUCN Red List status – DD.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1516FFB2AB9FD097FD8CFA4B.taxon	distribution	Distribution. Central Vietnam (Da Nang City Area). Endemic. Note. This species, very curious for its unusual column and pollinarium structure, was described thirty years ago on the basis of rather insufficient material collected from cultivated plants originating from Son Tra Island. Recently, it was rediscovered on the continent also near Da Nang City in forest of Ba Na Mountain in 20 km to the SW from the locus classicus. The new collection provides additional data on the floral morphology of this extremely rare species, which is presented below in the form of an amended description and fig. 2. More surveys are needed to check the presence of this species in adjoining areas. Accordingly, based on IUCN (2019) C. exuestre should be formally estimated as Data Deficient – DD. Amended description. Flowers not widely opening, campanulate, (9.5) 10 – 11 (11.5) mm across; sepals and petals rather fleshy, glabrous, white with two broad purple-brown longitudinal stripes, or with entirely purple-brown center; lip including spur white, with few purple speckles on lobes, bright yellow at base. Sepals obovate, concave, blunt to obtuse, (6) 6.2 – 6.4 (6.5) mm long, (3.6) 3.8 – 4.2 (4.4) mm wide, median sepal cucullate, lateral sepals slightly oblique. Petals narrowly obovate, almost flat, blunt to round at apex, (5.4) 5.6 – 6 (6.2) mm long, (2) 2.2 – 2.4 (2.6) mm wide, slightly oblique. Lip spurred, (6.8) 7 – 7.8 (8) mm long (from spur apex to the apex of epichile), 3 - lobed; sidelobes broadly triangular, obtuse, forward protruding, 2.4 – 2.5 mm long and wide at the base; median lobe fleshy, halfglobular, 2 – 2.2 mm long, 3 – 3.5 mm wide, forward directed, round or obscurely trilobe at apex, at base with prominent uprising conoid callus; spur saccate, almost parallel to ovary, 4 – 4.2 mm long, 2.8 – 3 wide, slightly dorso-ventrally flattened, with round, slightly emarginate apex and incomplete longitudinal septum inside. Back-wall callus in form of large, erect, T-shaped, flattened, papillose outgrowth about (1.6) 1.8 – 2 (2.2) mm tall, at apex with two recurved conoid horns, at base connected with fleshy side-lobes by fleshy papillose rollers. Column short, broad, obscurely cubic, (3.6) 3.8 – 4 (4.2) mm high, (1.8) 2 – 2.2 (2.4) mm wide, at front with small rostellum lobes supporting viscidium horns; stigma in form of transversely oblong hollow. Anther cap helmet shaped, skinny, sac-like, 2.2 – 2.4 mm tall and wide, without beak. Pollinia 2, each deeply split into 2 half-globular bodies. Stipe (tegula) in form of circular scarious plate 1.8 – 2 mm in diameter (being flattened), enveloping pollinia in form of narrow funnel after removing anther cap, viscidium in form of two narrow subulate forward directed acute horns 0.8 – 0.9 mm long. Studied specimen. Vietnam, Da Nang City Area, Ba Na Mt., evergreen broad-leaved forest at elevation of 300 – 400 m a. s. l., epiphyte, rare, June 2019, Nguyen Van Canh, AL 1123 a (LE 01167438 https: // en. herbariumle. ru /? t = occ & id = 133067, drawings LE 01123081 https: // en. herbariumle. ru /? t = occ & id = 133320, photos LE 01123087 https: // en. herbariumle. ru /? t = occ & id = 134257).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1516FFB1AB9FD613FD20F7AF.taxon	description	(Figs. 3, 4)	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1516FFB1AB9FD613FD20F7AF.taxon	materials_examined	Type: — VIETNAM. N Vietnam, Lang Son Province, Binh Gia District, Thien Long Commune, forest on karstic limestone mountain near Lan Luong Village, 18 April 2019, Truong Ba Vuong, Hoang Minh Tuan, BV 355 a (holotype VNM, isotype LE 01066647 https: // en. herbariumle. ru /? t = occ & id = 133883, authentic photos LE 01073485 http: // en. herbariumle. ru /? t = occ & id = 17628, drawings LE 01123082 https: // en. herbariumle. ru /? t = occ & id = 133321).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1516FFB1AB9FD613FD20F7AF.taxon	etymology	Etymology. The species name refers to the furcate apices of the lip side-lobes.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1516FFB1AB9FD613FD20F7AF.taxon	description	Description. Herb perennial monopodial epiphytic. Stem simple or basally few branched, semi-woody, pendulous, (10) 12 – 18 (20) cm long, terete or slightly flattened, (3.8) 4 – 5 (5.2) mm in diameter, with (3) 4 – 6 (8) leaves near the apex, in basal part with few wiry, straight or flexuose dull gray roots branching distally; internodes (0.6) 0.8 – 1.2 (1.4) cm long. Leaves subdistichous, sessile, dorsiventral, leathery, straight or slightly recurved and twisted, lanceolate, (5) 7 – 10 (12) cm long, (0.8) 0.9 – 1 (1.2) cm wide, obtuse and unequally shortly bilobed at apex. Inflorescence lateral raceme or few branching panicle, (8) 10 – 20 (25) cm long, scape and rachis green, speckled with purple to dirty purple; scape (6) 8 – 15 (18) cm long, pendulous, slightly flexuose to almost straight, with 2 – 4 short, tubular, brownish gray sterile bracts, simple or with 2 – 3 (4) branches; rachis (4) 6 – 14 (16) cm long, straight to distinctly zig-zag, with (3) 5 – 15 (18) spirally arranged, lax flowers distant on (4) 5 – 14 (16) mm. Floral bracts dull brown, minute, triangular, acute, 1.2 – 1.5 mm long, 1 – 1.2 mm wide. Pedicel and ovary terete, longitudinally grooved, (5) 5.5 – 7 (8) mm long, (0.9) 1 (1.2) mm in diameter, glabrous, dull purple, slightly broadening at the base. Flowers widely opening, (7) 8 – 10 (11) mm across; sepals and petals somewhat fleshy, glabrous, spreading, pale yellow with purple- or brownish-violet margin; lip white, bright yellow at base, with violet median lobe and purple-violet apices of side-lobes, spur white; column white with yellow base; anther cap white; pollinia yellow. Sepals obovate, concave, blunt to rounded at apex, (5) 5.5 – 6 (6.5) mm long, (3.3) 3.5 – 4 (4.2) mm wide, median sepal cucullate, lateral sepals slightly oblique. Petals narrowly obovate, almost flat, blunt to round at apex, (3.6) 3.8 – 4.2 (4.4) mm long, 2.4 – 2.6 mm wide, slightly oblique. Lip spurred, (5.8) 6 – 6.2 (6.4) mm long (from spur apex to the apex of epichile), 3 - lobed; side-lobes narrowly conoid, twisted on 90 º and furcate at apex, parallel and forward protruding, (1.7) 1.8 – 2 (2.1) mm long, (1) 1.2 (1.4) mm wide at the base, outside finely verruculose; median lobe very fleshy, almost half-globular in outline, (2.8) 3 (3.2) mm long, 2.8 – 3 mm wide, forward directed or slightly upright, apiculate, with short uprising mucro, disc at base with fleshy longitudinal keel continuing into the spur in form of spur septum; spur saccate, almost parallel to ovary, (1.7) 1.8 – 2 (2.1) mm long, (1.8) 2 (2.2) wide, slightly dorso-ventrally flattened, with entire, round apex and incomplete longitudinal septum inside. Back-wall callus in form of large, erect, T-shaped, flattened, papillose outgrowth about 1.2 – 1.4 mm tall, at apex with two recurved conoid teeth or horns, at base connected with fleshy side-lobes by fleshy papillose ridges. Column short, broad, indistinctly cubic, (2.4) 2.5 – 3 (3.2) mm high, (1.8) 2 (2.2) mm wide, at front with small rostellum lobes supporting viscidium horns; stigma in form of transversely oblong hollow. Anther cap helmet shaped, thin-walled, skin-like, 1.6 – 1.8 mm tall and wide, without beak. Pollinia 2, each deeply split into 2 half-globular bodies. Stipe (tegula) in form of rhomboid scarious plate 1.5 – 1.8 mm long and wide (being flattened), enveloping pollinia in form of narrow funnel after removing anther cap, viscidium in form of two narrow subulate forward directed acute horns 0.8 – 0.9 mm long. Fruits unknown. Habitat, phenology and conservation status. Epiphyte. Broad-leaved evergreen forests on karstic limestone. Fl. April. Very rare. Suggested IUCN Red List status – CR.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1516FFB1AB9FD613FD20F7AF.taxon	distribution	Distribution. Northern Vietnam (Lang Son Province, Binh Gia District). Endemic. Note. This species belongs to Cleisostoma sect. Paniculata Seidenf. (Seidenfaden, 1975, 1992), which is represented in eastern Indochina with five species, namely C. chapaense, C. duplicilobum, C. equestre, C. inflatum and C. paniculatum (Averyanov et al. 2015 b). Among them the new species is closest to C. equestre sharing such specific characters as the shape of lip lobes; similar T-shaped back-wall callus; skin-like anther cap tightly fitting the abaxial surface of the pollinarium stipe; flat, broad, plate-like pollinarium stipe covering the pollinia from above (like an umbrella); and prominent subulate forward directed horns of viscidium. This combination of characters has never been observed in other species of the genus. At the same time, the new species differs from C. equestre in: stem to 20 cm long (vs. stem about 5 cm long), leaves lanceolate 0.8 – 1.2 cm wide (vs. leaves broadly lanceolate 1.5 – 2 cm wide), inflorescence to 27 cm long, sometimes branching (vs. inflorescence to 25 cm long, simple), background of sepals and petals pale yellow, lip median lobe violet (background of tepals white, lip median lobe white), lip side-lobes narrowly conoid, twisted on 90 º, furcate at apex (vs. side-lobes broadly triangular, not twisted, entire at apex), median lip lobe at the base without callus, at apex apiculate, with short ascending mucro (vs. median lobe with prominent conoid callus at the base, apex almost flat, without ascending mucro), column 2.4 – 3.2 mm high with anther cap 1.6 – 1.8 mm tall (vs. column 3.6 – 4.2 mm high, anther cap 2.2 – 2.4 mm tall), and flattened stipe rhomboid, as long as wide (vs. flattened stipe circular). The new species is probably a strict endemic of the central part of the South Chinese floristic province as circumscribed by Averyanov et al. (2003). It was discovered in Vietnam near the Chinese border, hence it may be also found in similar limestone areas of Yunnan and Guangxi. Up to now, the species has found in only one locality, where less than 50 mature plants were observed. No more samples of this species were detected in the area during additional floristic explorations. Such conditions meets IUCN criteria (2019) that formally identify conservation status of new species as Critically Endangered – CR D. Several plants in the studied population with pure white flowers represent a true albino form: Cleisostoma furcatum Aver & Vuong forma albiflora Aver & Vuong, forma nov. Type: — VIETNAM. Lang Son Province, Binh Gia District, Thien Long Commune, forest on karstic limestone mountain near Lan Luong Village, 18 April 2019, Truong Ba Vuong, Hoang Minh Tuan, BV 355 b (holotype VNM), photos LE 01061302 http: // en. herbariumle. ru /? t = occ & id = 12496. Diagnosis: — new form differs from the type in pure white flowers except bright yellow base of the lip and column (vs. sepals, petals and lip heavily marked with dark violet).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151AFFBAAB9FD097FD08FE13.taxon	description	(Figs. 5, 6)	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151AFFBAAB9FD097FD08FE13.taxon	materials_examined	Type: — VIETNAM. Lam Dong Province, Dalat City area, 20.04.2019, Truong Ba Vuong, Ngo Quang Dang, BV 407 (holotype VNM, isotype LE 01123083 https: // en. herbariumle. ru /? t = occ & id = 133322). Authentic photos and drawings: — VIETNAM. LE 01123084 https: // en. herbariumle. ru /? t = occ & id = 133330, LE 01123083 https: // en. herbariumle. ru /? t = occ & id = 133322.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151AFFBAAB9FD097FD08FE13.taxon	etymology	Etymology. The species name refers to its relatively small flowers.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151AFFBAAB9FD097FD08FE13.taxon	description	Description. Herb perennial monopodial epiphytic. Stem simple or basally few branched, pendulous and somewhat distally ascending, (1) 2 – 4 (5) cm long, terete, (1.4) 1.5 – 2 (2.1) mm in diameter, covered by distichous leaf sheaths, with (4) 5 – 7 (8) leaves in apical half, in basal part with many wiry, twisted dull gray roots. Leaves subdistichous, sessile, joined, broadly lanceolate to narrowly elliptic, grassy green, (1.2) 1.5 – 2 (2.5) cm long, (2.5) 3 – 5 (6) mm wide, spreading horizontally, apex obtuse, sometimes shortly unequally bilobed. Inflorescence axillary lax raceme, glabrous, (1.5) 2 – 3.5 (4) cm long; peduncle greenish to dull purple, thin, terete, (0.8) 1 – 1.8 (2) cm long, naked or with 2 – 3 distant, sterile triangular, acute bracts, 1 – 2 mm long and wide; rachis terete, slightly longitudinally angled with (3) 4 – 11 (12) flowers distant on (0.5) 1 – 3 (3.2) mm; floral bracts, triangular, acute, (0.5) 0.6 – 0.7 (0.8) mm long, 0.4 – 0.5 mm wide. Flowers subsessile, spirally arranged, spreading at right angle to rachis, opening in succession, (3) 3.2 – 3.8 (4) mm across, sepals and petals glabrous, pale yellow, each with two obscure reddish-brown strips, lip white with dull purple marks on epichile, column white or little greenish, anther cap light yellow. Pedicel and ovary light green, glabrous, terete, shallowly grooved, (1.8) 2 – 3 (3.5) mm long, (0.4) 0.5 (0.6) mm in diameter. Sepals concave, obtuse to blunt at apex; median sepal ovate, (1.8) 2 (2.2) mm long, (1.1) 1.2 (1.3) wide (being flattened), cymbiform, dorsally gibbous and hooded; lateral sepals broadly obovate, slightly oblique, (2.1) 2.2 (2.3) mm long, (1.7) 1.8 (1.9) wide, almost round at apex. Petals concave, obtuse to blunt at apex, ovate, (1.7) 1.8 – 2 (2.1) mm long, (0.9) 1 (1.1) mm wide. Lip simple or obscurely 3 - lobed, spurred, (3.8) 4 – 4.2 (4.4) mm long from apex of the lip to apex of spur, firmly fused by lateral sides with column base, with spur lying almost parallel to ovary; epichile 1.5 – 1.6 mm long and wide, entire triangular or with obscure roundish side-lobes, at apex attenuate to small straight or down recurved acute seta 0.3 – 0.4 mm long, disk with 2 short parallel low keels; spur glossy white, shortly cylindrical, with no constriction, (2) 2.2 – 2.6 (2.8) mm long, (0.8) 1 (1.2) mm in diameter, oblique conical and round at apex. Column footless, erect, stout, 1 – 1.2 mm tall and wide, at front with 2 large forward directed conoid papillose bosses 0.7 – 0.8 mm long, 0.6 – 0.7 mm in diameter at the base; rostellum very small, placed between bosses; stigma large, concave, circular. Anther cap large, as tall and broad as column, half-globular, 1 - 2 mm in diameter, with narrowly triangular, down directed beak. Pollinia 2, globular, about 0.3 mm in diameter (0.15 – 0.2 mm when dry), with small groove on outer surface; stipe linear, translucent, longitudinally conduplicate, bent in the middle and suddenly much widening into broad plate with incurved lateral margins, 1.2 – 1.4 mm long, 0.8 – 0.9 mm wide in widest part; viscidium very small, ovate, about 0.1 mm long. Fruits unknown. Habitat, phenology and conservation status. Miniature monopodial canopy epiphyte. Primary evergreen broadleaved submontane forests. Fl. April. Very rare. Estimated IUCN Red List status – CR.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151AFFBAAB9FD097FD08FE13.taxon	distribution	Distribution. Southern Vietnam (Lam Dong province). Endemic. Notes. Like Malleola luongii Averyanov & V. C. Nguyen in Averyanov et al. (2018: 130) recently discovered in Vietnam, the new species belongs to the so-called Malleola dentifera – vietnamensis complex, taxa of which occur from Indochina and Peninsular Malaysia to the Greater Sunda Islands (O’Byrne, 2017). Our plant is closest to the type subspecies of M. vietnamensis Guillaumin (1964: 268), including M. dentifera J. J. Smith (1927: 191) as a synonym (O’Byrne 2017), in a general appearance and color scheme of the flower. It differs from M. vietnamensis var. vietnamensis discovered plant differs in the distinctly shorter stem 1 – 5 cm long (vs. stem normally 10 – 45 cm long), leaves 1.5 – 2.5 cm long (vs. leaves normally 3.2 – 10 cm long), inflorescence lax flowered, flowers 3 – 4 mm across (vs. inflorescence subdense, flowers 5.5 – 8.5 mm across), lip simple or with obscure roundish side-lobes (vs. lip distinctly 3 - lobed, side-lobes triangular acute forming forward directed teeth), lip disc with 2 short low keels, lip apex with small narrowly triangular straight or down curved seta (vs. disc with no ornamentation, lip apex attenuate to linear revolute or helicoid curved processus), spur shortly cylindric without constriction, 2 – 2.8 mm long (vs. spur commonly dorso-ventrally flattened in apical half, often constricted in apical half, 3.7 – 7 mm long), column at front with conical swellings (column with hemispheric swellings), pollinarium stipe 1.2 – 1.4 mm long (vs. pollinarium stipe 1.9 – 2 mm long), pollinia 0.3 mm in diameter to 0.2 mm in diameter when dry (vs. pollinia 0.4 – 0.9 mm in diameter). Only few specimens of the new species were found in densely populated area where most lands has been converted into agricultural plantations. Area of Occupancy (AOO) is estimated as 4 km 2, and as the result due to available data and observations the species should be preliminarily estimated as Critically Endangered – CR B 2 ab (iii) (IUCN 2019). It is noteworthy that like its allies, the new species exhibits certain apomorphic characters such as prominently inflated lateral stelidia and apically broadening pollinarium stipe. These features along with the subulate or caudate, downward revolute lip apex, lack of distinct calli in spur and almost entire pollinia set this group apart from the related genus Robiquetia Gaudichaud-Beaupré in Freycinet (1829: 426), with which Malleola has been merged on the basis of molecular data (Kocyan and Schuiteman, 2014).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151EFFB9AB9FD1EBFB10FE5B.taxon	description	(Figs. 8 A, B)	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151EFFB9AB9FD1EBFB10FE5B.taxon	materials_examined	Type: — BANGLADESH. Sylhet, Wallich 7301 (syntypes K 001127133 & K 001127134).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151EFFB9AB9FD1EBFB10FE5B.taxon	biology_ecology	Habitat, phenology and conservation status: — Epiphyte. Broad-leaved evergreen. Fl. February – March. Very rare. Suggested IUCN Red List status – DD.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151EFFB9AB9FD1EBFB10FE5B.taxon	distribution	Distribution: — Northern Vietnam (Thanh Hoa Province, Quan Son District), NE India, Bangladesh, E China.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151EFFB9AB9FD1EBFB10FE5B.taxon	discussion	Note: — The distribution and conservation status of this species here newly recorded from Vietnam remains very unclear. Its discovery in Vietnam is not surprising as it was recorded from adjacent regions of mainland China and from Taiwan (Zhou et al. 2016, Lin et al. 2016). Meanwhile, without flowers, it may be easily confused with the widespread and common species, P. spicatum Breda (1827 t. 15). Hence, the distribution of this rather unattractive species in Vietnam may be much broader than it is indicated by this single record. As a result, the conservation status of this species should be assessed as the Data Deficient – DD, according to the formal IUCN criteria (IUCN 2019).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151EFFB9AB9FD1EBFB10FE5B.taxon	materials_examined	Studied specimens: — VIETNAM, Thanh Hoa Province, Quan Son District, Pu Man Forest, epiphyte, leaf margin undulate, apex unequally 2 - lobed, flowers glabrous, slightly fragrant, tepals white, purple spotted, lip white, 26.02.2020, Truong Ba Vuong, BV 517 (LE 01073013 https: // en. herbariumle. ru /? t = occ & id = 14362).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151DFFB8AB9FD223FAD8FA9E.taxon	description	(Fig. 7)	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151DFFB8AB9FD223FAD8FA9E.taxon	materials_examined	Type: — VIETNAM. Type herbarium specimen prepared on 25 April 2020 by L. Averyanov, T. Maisak, AL 410 from cultivated plants collected in Lam Dong Province, Bidoup Nui Ba National Park, evergreen broad-leaved forest, at 1500 – 1600 m a. s. l. on 2 September 2018, Nguyen Van Canh (holotype LE 01068479 https: // en. herbariumle. ru /? t = occ & id = 16592). Authentic photos: — VIETNAM. Photos are made on 25 April 2020 by L. Averyanov, T. Maisak, AL 410 from cultivated plants collected in Lam Dong Province, Bidoup Nui Ba National Park, evergreen broad-leaved forest, at 1500 – 1600 m a. s. l. on 2 September 2018, Nguyen Van Canh s. n. (LE 01122887 https: // en. herbariumle. ru /? t = occ & id = 99509, LE 01073077 https: // en. herbariumle. ru /? t = occ & id = 15213).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151DFFB8AB9FD223FAD8FA9E.taxon	etymology	Etymology: — The species name refers to Mr. Do Tuan Hung for his great contribution to the conservation of Vietnamese orchids.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151DFFB8AB9FD223FAD8FA9E.taxon	description	Description: — Herb miniature monopodial, branch and canopy epiphyte. Stem simple, suberect or ascending (3) 4 – 6 (7) cm long, leafy in apical two thirds, with internodes (1.8) 2 – 4 (4.5) mm, leafless in basal part, (2) 2.5 (3) mm in diameter, with few, flexuose whitish roots near the base. Leaves grassy green, finely rugose, sessile, very fleshy, spreading at a wide angle to stem, arching, subterete, adaxially grooved, (1.5) 2 – 3 (3.5) cm long, (1.8) 2 – 2.8 (3) mm in diameter, acute, slightly constricted near of articulation with leaf sheath; leaf sheaths equitant, rigid, verruculose, completely covering the stem. Inflorescence axillary, suberect or ascending raceme, rarely 1 – 2 branched panicle, (5) 5.5 – 6.5 (7) cm long, scape and rachis light grassy green; scape (2) 2.5 – 3.5 (4) cm long, more or less straight; rachis straight or somewhat arching, thin, slightly angled, (1) 2 – 3 (3.2) cm long, with many spirally arranged, subdense flowers, distant at (0.6) 1 (1.4) mm. Floral bracts relatively large, white, light green along median rib, rhomboid, (1.8) 2 – 2.5 (2.7) mm long, (1.7) 1.8 – 2 (2.2) mm wide, shortly fimbriate along the margin, cuspidate, with prominently attenuate apex. Pedicel and ovary light green, (1.2) 1.3 – 1.4 (1.5) mm long, about 0.4 – 0.5 mm in diameter, terete, glabrous. Flowers odorless, tubular, with recurved apical third of sepals and petals, (1.6) 1.8 – 2 (2.2) mm across; sepals white, median sepal with purple apex, lateral sepals with purple median longitudinal stripe; petals entirely bright purple, lip including spur snow-white, column green, anther cap and pollinia bright yellow. Sepals narrowly ovate, little concave, dorsally slightly carinate, blunt to roundish at apex, (1.5) 1.6 – 1.8 (1.9) mm long, 0.6 – 0.7 mm wide, lateral sepals slightly oblique. Petals oblong broadly lanceolate, rounded to blunt at apex, as long as median sepal, 0.3 – 0.4 mm wide, distally strongly recurved. Lip spurred, (2.6) 2.8 – 3 (3.2) mm long (from spur apex to the apex of median lobe), almost entire; median lobe very fleshy, narrowly obovate (when look from below), rhomboid (from side view), 1.4 – 1.6 mm long, 0.5 – 0.6 mm wide, round at apex, straight, forward directed; at the base with 2 massive fleshy lateral longitudinal rollers almost completely closing entrance to the spur. Spur shortly conoid, slightly upcurved, parallel to ovary, (1) 1.1 – 1.2 (1.3) mm long, about 0.5 mm wide, with no longitudinal septum or back-wall callus inside. Column stout, very short, 0.2 – 0.3 mm tall and wide, with no wings; rostellum very small, broad, forward directed; stigma obscurely triangular to roundish. Anther cap, hemispherical, 0.2 – 0.3 mm in diameter, with prominent triangular, obtuse, forward directed beak about 2 mm long. Pollinarium 1, with 2 pollinia, flat oblong stipe (tegula) and flat oblong narrowly ovate viscidium. Pollinium ovoid or globular, splitting into 2 unequal hemiovoid lobes. Fruit unknown. All measurements were taken on fresh floral parts, which become about 1 / 3 smaller after exsiccation in process of herbarium specimen preparation (Averyanov et al. 2019 e). Habitat, phenology and conservation status: — Miniature branch and canopy epiphyte on tall mossy trees. Evergreen broad-leaved submontane and montane forests at 1000 – 1800 m a. s. l. Rare. Flowers in April – May, October – November. Suggested IUCN Red List status – EN.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151DFFB8AB9FD223FAD8FA9E.taxon	distribution	Distribution: — VIETNAM, Lam Dong Province (Lac Duong and Lam Ha districts). Endemic. Notes: — The new species, like Schoenorchis tatonii Aver. in Averyanov et al. (2019: 295) recently described from the same area, represents one another local sympatric race of the widespread S. gemmata (Lindley 1838: 50) J. J. Smith (1912: 100) endemical to the mountain area known in Vietnamese geography as Central Highlands, or Tay Nguyen Plateau (Averyanov et al. 2003). In its morphology the new species clearly differs from S. gemmata in the small dimensions of the whole plant, with the stem 3 – 7 cm long having internodes (1.8) 2 – 4 (4.5) mm (vs. stem 5 – 15 cm long, with internodes 7 – 15 mm long), fleshy, subterete leaves 1.5 – 3.5 cm long and 1.8 – 3 mm in diameter (vs. distinctly dorso-ventrally flattened, conduplicate, more or less flat, 5 – 10 cm long, 5 – 12 mm wide), inflorescence simple, rarely 1 – 2 branched, 5 – 7 cm long (vs. inflorescence almost always branching, 8 – 15 cm long), floral bracts relatively large, rhomboid, cuspidate, enveloping pedicel and ovary, reaching middle of median sepal, much longer than ovary, finely fimbriate along the margin (vs. floral bract small, triangular, acute, not enveloping and twice shorter than pedicel and ovary, with entire margin), pedicel and ovary light green, 1.2 – 1.5 mm long (vs. pedicel and ovary green to dirty violet, about 3 mm long), flowers (1.6) 1.8 – 2 (2.2) mm across, sepals and petals distinctly recurved in apical half (vs. flowers 3 – 4 mm across, sepals and petals straight or slightly recurved at apex), sepals white with purple apex of median sepal and light purple stripe on lateral sepals, petals bright purple, lip including spur white (vs. sepals and petals entirely dull lilac violet, lip white often with lilac violet tint), sepals and petals 1.5 – 1.9 mm long (sepals and petals 2 – 2.5 mm long), lip almost entire, narrowly obovate, hardly broadening from hypochile, 0.5 – 0.6 mm wide (vs. obscurely lip 3 - lobed, median lobe broadly obovate or flabellate rhomboid, twice broader than hypochile, 1 – 1.2 mm wide), spur 1 – 1.3 mm long, about 0.5 mm wide (spur about 2 mm long and 1.5 mm wide), and column 0.2 – 0.3 mm tall (vs. column 0.6 – 0.8 mm tall). Schoenorchis hungii is undoubtedly very rare. Up to now it was collected only in three close localities in the densely populated and currently highly urbanized Lac Duong and Lam Ha districts of Lam Dong Province in the center of southern Vietnam. Taking into consideration the vast deforestation in both provinces the estimated extent of occurrence (EOO) is probably limited by the territory of Bidoup – Nui Ba National Park. In this connection, it cannot be larger than 700 km 2 area of occupancy (AOO) is 12 km 2 in terms of IUCN (2019). According to available data and following to criteria proposed by IUCN the conservation status of the new species may be preliminarily estimated as Endangered – EN B 2 ab (iii) (IUCN 2019). Studied specimens: — VIETNAM, herbarium specimen prepared on 10.11.2019 by L. Averyanov, AL 1221 from cultivated plant collected in Lam Dong Province, Lam Ha District, evergreen broad-leaved submontane forest at elevation about 1000 m a. s. l., epiphyte on tall trees, Ngo Quang Dang s. n, 28 October 2019 LE 01066612 https: // en. herbariumle. ru /? t = occ & id = 12381. VIETNAM, Lam Dong Province, Bidoup Nui Ba National Park, Bidoup Mountains, primary evergreen broad-leaved forest at elevation 1700 – 1800 m a. s. l., epiphyte on tall mossy tree, not common. 2019, Nguyen Van Canh, AL 1113, LE 01167750 https: // en. herbariumle. ru /? t = occ & id = 133079.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151CFFA7AB9FD56FFE49FE7F.taxon	materials_examined	Type: — INDONESIA. W Java “ Rchb. fil. Provinz Bandong. Zollinger Sine Nr. ” (W? not seen). Habitat, phenology and conservation status: — Epiphyte. Broad-leaved evergreen lowland and submontane forests on granite at elevation 600 – 800 m a. s. l. Fl. October – November. Rare. Suggested IUCN Red List status – EN.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F151CFFA7AB9FD56FFE49FE7F.taxon	distribution	Distribution: — Southern Vietnam (Dak Lak and Lam Dong provinces), Thailand, Malaysia, Indonesia, Philippines, New Guinea, NE Australia. Note: — This widespread species with fugacious, very short lived flowers attracts little attention from orchid collectors and is poorly represented both in living and herbarium collections. Its two documented locations in Dak Lac province (Chu Mu and Chu Yang Sinh Mountains) and two in Lam Dong province (both in Dalat Town area) indicate an area of occurrence (EOO) in Vietnam less than 5000 km 2. All observed populations are very small and surely form very small area of occupancy (AOO) due to severe fragmentation of suitable environment as a result of intensive deforestation and agricultural land development throughout the distribution area. The wide loss of habitats are strong factors that identify the conservation status of this species in Vietnam as nationally Endangered – EN B 1 ab (iii), B 2 ab (iii) according to formal IUCN criteria (IUCN 2019). Studied specimens: — VIETNAM, Lam Dong Province, Dalat Town area, 16.05.2000, L. Averyanov s. n. (LE 01076678 https: // en. herbariumle. ru /? t = occ & id = 57557). VIETNAM, Lam Dong Province, wild collected plant cultivated in Dalat Town private collection, Dang s. n. photo, 2010 (LE 01122321 https: // en. herbariumle. ru /? t = occ & id = 82807). VIETNAM, herbarium specimen and photos prepared on 19 October 2017 by L. Averyanov and T. Maisak, AL 335 from plant collected by Nguyen Van Canh, s. n., in Dak Lak Province, M Drac District, Chu Mu Mountain, at 600 – 800 m a. s. l. on 15 September 2016 (LE 01076423 https: // en. herbariumle. ru /? t = occ & id = 57303, LE 01076427 https: // en. herbariumle. ru /? t = occ & id = 57307, LE 01122490 https: // en. herbariumle. ru /? t = occ & id = 82980). VIETNAM, herbarium specimen on 30 October 2018 by L. Averyanov, T. Maisak, AL 100 from plant collected by Nguyen Van Canh s. n. in Dak Lak Province, Chu Yang Sinh Mountains on 30 November 2015, flowers white, with light sweet fragrance; each tepal with brown round spot near the base; lip with yellow spot at the disc and brown spots on sides; column white with brown spot on lateral sides; anther white (LE 01076428 https: // en. herbariumle. ru /? t = occ & id = 57308).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1503FFA7AB9FD20FFA52F993.taxon	materials_examined	Type: — INDONESIA. Java: Bobodjong (J. J. S.); Goenoeng Batoe (not located). Habitat, phenology and conservation status: — Epiphyte. Broad-leaved evergreen lowland forests at elevations 300 – 400 m a. s. l. Fl. April – June. Very rare. Suggested IUCN Red List status – EN.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1503FFA7AB9FD20FFA52F993.taxon	distribution	Distribution: — Southern Vietnam (Dong Nai, Dak Lak and Lam Dong provinces), Thailand, Cambodia, Malaysia, E Indonesia. Note: — The discovery of this species in three locations in Dak Lak, one in Lam Dong, and one in Dong Nai Provinces is not much surprising. Vietnamese records naturally extend the known area of this species typical for lowland warm-loving forests of the southern part of Indochinese Peninsula to the east. Field observations in all recorded locations indicate this species in Vietnam as a very rare plant presented by very small, highly fragmented populations. According to discovered locations closely allied to each other, the area of its occurrence (EOO) in Vietnam are surely less than 10000 km 2, and the area of the species occupancy (AOO) in all five known populations may be very small due to intensive deforestation and agricultural land exploitation in the area of the species occurrence. The wide loss of habitats identify the tentative conservation status of this species as a nationally Endangered – EN A 3 (c), B 1 ab (i, iii), B 2 ab (i, iii) according to formal IUCN criteria (IUCN 2019). Studied specimens: — VIETNAM, Dac Lac Province, Buon Don District, Krong Na Municipality, Yok Don National Park, Yok Don Ridge around point 12 º 51 ’ 12 ” N 107 º 41 ’ 18 ” E, primary dry evergreen forest on thin gray soils derived from sandstone with quartzite dykes along ridge edge at elevation 300 – 350 m a. s. l., epiphyte on shady place, rare, 18 March 2008, N. T. Hiep, Averyanov L., P. K. Loc, N. T. Vinh, N. S. Khang, T. H. Thai, N. V. Trai HLF 7183, flowered in Hanoi in Hiep Garden at June 2009 (photos LE 01122270 https: // en. herbariumle. ru /? t = occ & id = 82753). VIETNAM, Dak Lac Province, Krong No, Nguyen Van Canh s. n. photo 06 June 2015 (photos LE 01122267 https: // en. herbariumle. ru /? t = occ & id = 82747). VIETNAM, Dak Lak Province, Krong Bong Commune, Pham Dinh Hiep, Nguyen Hoang Tuan s. n. 25.04.2018 (LE 01076457 https: // en. herbariumle. ru /? t = occ & id = 57337, photos LE 01087096 https: // en. herbariumle. ru /? t = occ & id = 18618). VIETNAM, Dong Nai Province, sine loc., 9 July 2020, Truong Ba Vuong, BV 685 (VNM, photos LE 01087104 https: // en. herbariumle. ru /? t = occ & id = 18627). VIETNAM, Lam Dong Province, Bao Loc District, 14 July 2020, Dinh Quang Diep, s. n. (photos LE 01087095 https: // en. herbariumle. ru /? t = occ & id = 18617)	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1503FFA5AB9FD66BFBD5FE37.taxon	description	(Fig. 9)	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1503FFA5AB9FD66BFBD5FE37.taxon	materials_examined	Type: — INDIA. Assam and Khasija, Griffith; base of Khasija, J. D. H. & T. T. 193 (syntypes K 000895706, K 000895708, K 000895709). Habitat, phenology and conservation status: — Epiphyte. Broad-leaved evergreen montane forests on granite at 1800 – 1900 m a. s. l. Fl. July – August. Rare. Suggested IUCN Red List status – VU.	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
038CE12F1503FFA5AB9FD66BFBD5FE37.taxon	distribution	Distribution: — Northern Vietnam (Lao Cai Province), Nepal, NE India, China. Note: — All three recorded localities of this species in Vietnam are adjacent to the Chinese part of the species range and slightly extend its area to the southeast. The area of the occurrence (EOO) of this species in Vietnam comprises highlands of Hoang Lien Son Range and adjacent mountains in parts of Lao Cai Province. The total extent of occurrence may be totally estimated as about 3200 km 2 where the species can survive on many steep mountain slopes inaccessible for the direct deforestation. Meanwhile, the species occupancy area (AOO) may be very small (far less than 500 km 2), as the species inhabit canopies of only the oldest emergent trees, which is why its subpopulations are highly fragmented. According to IUCN criteria the species conservation status in Vietnam may be estimated as nationally Critically Endangered – CR ab (iii) (IUCN 2019). Studied specimens: — VIETNAM, Lao Cai Province, flower yellow brown marked on tepals, lip side-lobes indistinct, spur terete, upcurved, nearly touching lip, 31 July 2018, Truong Ba Vuong BV 338 (LE 01073486 http: // en. herbariumle. ru /? t = occ & id = 17629). VIETNAM, Lao Cai Province, Bat Xat District, Y Ty Commune, Bat Xat Nature Reserve, 22 ° 37 ’ 28.8 ” N 103 ° 37 ′ 44.7 ″ E, 1838 m a. s. l., 1 August 2019, Bui Hong Quang, Tran Duc Binh (LE 01090928 https: // en. herbariumle. ru /? t = occ & id = 82373). VIETNAM, cultivated, wild collected plant originated from Lao Cai Province, herbarium specimen and photo prepared on 18 August 2020, Truong Ba Vuong, Ngo Quang Dang, Phan Trong Quyet, BV 790 (LE 01087405 https: // en. herbariumle. ru /? t = occ & id = 38804).	en	Averyanov, Leonid V., Thai, Tran Huy, Truong, Ba Vuong, Nguyen, Van Canh, Nguyen, Tuan Hoang, Maisak, Tatiana V., Nguyen, Khang Sinh, Nguyen, Van Khuong (2022): New orchids in the flora of Vietnam (Orchidaceae, Aeridinae). Phytotaxa 555 (2): 113-135, DOI: 10.11646/phytotaxa.555.2.1
