Appendicula spicata Aver. & Vuong

Averyanov, Leonid V., Nguyen, Van Canh, Vuong, Truong Ba, Nuraliev, Maxim S., Nguyen, Khang Sinh, Maisak, Tatiana V., Yudova, Daria A., Saidov, Nikita T., Nguyen, Cuong Huu & Nong, Duy Van, 2024, New orchids in the flora of Vietnam VIII (Orchidaceae: Epidendroideae, tribes Malaxideae, Neottieae and Podochileae), Phytotaxa 658 (1), pp. 1-49 : 32-36

Appendicula spicata Aver. & Vuong , sp. nov.

( Fig. 16 & 17 )

= A. hexandra (J.Koenig in Retzius 1791: 45) Smith (1932: 119) pro parte: Ho (1993: 979, fig. 9874, 2000: 799, fig. 10954), Seidenfaden (1975a: 9, 1992: 200), Averyanov (1988: 22, 1990: 27, 1994: 164, 2006: 51), Hop (1998: 64), Averyanov & Averyanova (2002: 53, 2003: 12).

= A. koenigii Hooker (1890: 84) , nom. illeg. (≡ A. hexandra ; see Seidenfaden 1973b, 1986b, 1995b), pro parte: Ho (1972: 1080, fig. 5208).

Diagnosis: —The new species differs from the morphologically most similar A. hexandra in inflorescence up to 2.5–3.5 cm long, twice as long as leaves or longer, in continuously elongating rachis usually bearing numerous (more than 30) flowers, lip and column with purple spots on sides, and in almost circular to broadly obovate lip callus with small lateral folds at base.

Type: — VIETNAM. Khanh Hoa Province: Cam Lam District, Hon Ba Nature Reserve, around point 12°06.834’N 108°59.565’E, epiphyte in shady riparian forest on granite at elevation of about 361 m a.s.l., along small stream, 9 June 2017, Truong Ba Vuong, BV 285 (holotype LE LE 01054912! https://en.herbariumle.ru/?t=occ&id=5788, isotypes LE LE 01054910! https://en.herbariumle.ru/?t=occ&id=5786, VNM!).

Etymology: —The species name refers to its long spicate inflorescence.

Description:—Herb clustering, epiphytic or lithophytic. Stem suberect to pendulous, (16)18–26(30) cm long, (1)1.2–1.4(1.6) mm in diameter,glabrous, leafy throughout,densely covered by imbricate leaf sheaths. Leaves distichous, spreading, sessile, glabrous, with papyraceous tubular sheaths enveloping stem; leaf blade pale green, narrowly ovate to narrowly triangular oblong, (0.9)1–1.6(1.7) cm long, (4)4.5–7(8) mm wide, shallowly emarginate and minutely apiculate. Inflorescence an axillary spike (often pseudoterminal), 2.5–3.5 cm long (when fully developed), twice as long as leaves or longer, many-flowered (usually with more than 30 flowers), with flowers developing successively and 2–3(4) of them open at once; peduncle 2–4 mm long, glabrous, covered by 2–4 tubular papyraceous sterile bracts; rachis commonly bent at the base, straight or slightly flexuose, spreading or pendulous, glabrous, densiflorous. Floral bracts triangular or triangular narrowly ovate, acute, deflexed, (1)1.2–1.6(1.8) mm long, (0.4)0.5–0.7(0.8) mm wide, glabrous, pure white, soon becoming light brownish, papyraceous. Flowers sessile, white, lip and column with purple spots on sides. Ovary not resupinate, white to white with greenish tint, terete, distally slightly broadening, (1.5)1.6– 1.9(2) mm long, 0.2–0.3 mm in diameter, glabrous. Sepals ovate, somewhat cymbiform, blunt to obtuse at apex, (2)2.2–2.7(3) mm long, (1.4)1.6–2(2.4) mm wide, outside sometimes with scattered small brownish scurfy hairs, inside glabrous; lateral sepals slightly oblique, distinctly wider than median sepal, forming almost globular or emarginate mentum 1–1.2 mm long and wide. Petals oblong narrowly obovate, as long as sepals but slightly narrower, blunt or roundish at apex, glabrous. Lip broadly oblong, cymbiform, (2.2)2.4–2.6(2.8) mm long, (1.4)1.6–1.8(2) mm wide, subglobose at base, broadly triangular to blunt or obtuse at apex; basal callus retrorse, flat, almost circular to broadly obovate, with small lateral folds at base. Column stout, 1.4–1.5 mm tall; rostellum broadly conoid, about 0.8 mm long; anther cap bail-shaped, placed behind; column foot 0.6–0.8 mm long, forward directed. Fruit a capsule, fusiform to narrowly obovoid, 6–8 mm long, with 3 low longitudinal ribs.

Ecology and phenology: —Clustering epiphyte an lithophyte. Primary and old secondary humid evergreen broad-leaved lowland and submontane forests on granite, shale and sandstone at elevations of 200–1150 m a.s.l. Locally common. Flowers in March–June, November–December.

Distribution: —Endemic to Vietnam: provinces Ha Tinh (Huong Son District), Quang Binh (Minh Hoa District), Thua Thien Hue (districts A Luoi, Huong Thuy, Nam Dong, Phu Loc), Quang Nam (Song Thanh Nature Reserve), Gia Lai (K’Bang District), Dak Lak (Chu Yang Sinh Mountains), Khanh Hoa (Hon Ba Nature Reserve), Ninh Thuan (Ninh Hai District).

Conservation status: —In almost all its known locations, Appendicula spicata was observed to be locally common and even abundant. Accordingly, we preliminarily estimate the conservation status of this species as Least Concern (LC).

Notes: —For a long time, Appendicula spicata has been misidentified in botanical surveys in Vietnam as A. hexandra ( Seidenfaden 1975 a, 1992, Averyanov 1988, 1990, 1994, 2006, Ho 1993, 2000, Hop 1998, Averyanov & Averyanova 2002, 2003). The latter species is known from Thailand, Cambodia, Vietnam and Sumatra ( Comber 2001, Averyanov 2013, Averyanov et al. 2016, Chantanaorrapint 2022). The two species can therefore occur sympatrically in Vietnam. These species share superficially fairly similar flowers and are probably connected by natural hybridization, as soon as the plants with intermediate morphology occur; such plants are difficult for identification, particularly in herbarium collections. Meanwhile, living flowering specimens of the new species readily differ from A. hexandra (comprehensive descriptions and drawings of which are presented by Seidenfaden 1992 and Chantanaorrapint 2022) in inflorescence 2.5–3.5 cm long, twice as long as the leaves or longer (vs. inflorescence commonly 1.5–2.5 cm long, two times shorter than the leaves or shorter), rachis continuously elongating, many-flowered, usually with more than 30 flowers (vs. rachis not continuously elongating, few-flowered, usually with 2–10 flowers), flowers pure white, lip and column with purple spots on sides (vs. flowers uniformly white with a green tint to light greenish), basal callus of lip almost circular to broadly obovate, with small lateral folds at the base (vs. basal callus of lip oblong ovate, without lateral folds at the base). In addition, flowering shoots of A. spicata curiously resemble those of the predominantly Malesian species A. pendula Blume (1825: 298) , which has long pendulous inflorescences ( Comber 1990, 2001, Chantanaorrapint 2022). Appendicula spicata differs, however, from the latter species in having much smaller stems and leaves.

Appendicula annamensis Guillaumin (1930: 340) and A. inornata Guillaumin (1961: 562) described from southern Vietnam were treated by Seidenfaden (1975a, 1986b, 1992) as synonyms of A. hexandra . Based on the studies of the type collections and protologues, we agree with his opinion. At the same time, the plants recorded for Hainan (S China) under the name A. annamensis ( Ormerod 2004, Chen et al. 2009, Zhou et al. 2016, Jin et al. 2023) possibly belong to A. spicata according to their reported characters. The blackish leaves of the dried specimens that are indicated as a diagnostic character of A. annamensis by Chen et al. (2009) are likely to be a consequence of certain conditions of herbarium preparation, and seem to lack any taxonomic significance.

Additional specimens studied (paratypes):— VIETNAM. Ha Tinh Province: Huong Son District, Son Kim Municipality, Rao Bun stream, around point 18º23’39’’N 105º15’12’’E, primary broad-leaved evergreen closed wet forest on very steep shale slopes of river canyon at elevation about 300 m a.s.l., epiphyte on trees along stream, flowers white, light greenish, lip white-yellowish, with purple side lobes, common, 2 May 2004, P. K. Loc, L. Averyanov, P. V. The, N. T. Vinh, HAL 5016 ( LE LE 01054933 https://en.herbariumle.ru/?t=occ&id=5808, LE 01054945 https://en.herbariumle.ru/?t=occ&id=5820, photos LE LE 01073293 https://en.herbariumle.ru/?t=occ&id=15903). VIETNAM. Quang Binh Province: Minh Hoa District, Dan Hoa Municipality, Vietnam-Laotian border, around Cha Lo border gate, point 17°41’50”N 105°45’54”E, primary broad-leaved forest on steep rocky mountain slopes composed with ochre-brown shale at elevation 300–450 m a.s.l., lithophyte on shady mossy boulders, white to yellowish, very common, 18 April 2008, L. Averyanov, P. K. Loc, N. T. Vinh, N. S. Khang, HAL 11648 ( LE LE 01054883 https://en.herbariumle.ru/?t=occ&id=5759, photos LE LE 01073295 https://en.herbariumle.ru/?t=occ&id=15905). VIETNAM. Thua Thien Hue Province: A Luoi District, A Roang Municipality, Tra Lenh Forestry Department station, around point 16°04’41’’N 107°29’06’’E, primary closed evergreen broad-leaved forest on very steep mountain slopes composed with shale, sandstone and granite at elevation 700–800 m a.s.l., epiphyte on mossy trees along rocky stream valley, flowers white, lip with reddish hypochile, very common, 21 April 2005, L. Averyanov, P. K. Loc, J. Regalado, T. V. Thao, N. T. Vinh, HAL 7270 (photos LE LE 01073299 https://en.herbariumle.ru/?t=occ&id=15909). VIETNAM. Thua Thien Hue Province: Huong Thuy District, Duong Hoa Municipality, Huong Thuy forest enterprise territory, around point 16°12’50’’N 107°36’29’’E, mountain and hill slopes composed with shale at elevation of about 200–250 m a.s.l., fractionally logged primary and secondary closed evergreen broad-leaved forest on steep stream slopes, epiphyte and lithophyte along rocky stream valley, flowers white, locally abundant, 14 May 2005, L. Averyanov, P. K. Loc, T. V. Thao, N. T. Vinh, HAL 8252 ( LE LE 01054939 https://en.herbariumle.ru/?t=occ&id=5814). VIETNAM. Thua Thien Hue Province: Nam Dong District, Huong Son Municipality, around point 16°09’52’’N 107°36’22’’E (around plot 16°09’36’’N, 107°36’10’’E), heavily logged primary closed broad-leaved evergreen lowland forest along La Ma River on very steep hill slopes composed with clayey shale, at elevation about 300–450 m a.s.l., epiphyte on mossy trees along stream, very common, 26 March 2005, L. Averyanov, N. T. Hiep, P. K. Loc, P. V. The, A. Averyanova, N. T. Vinh, HAL 6914 ( LE LE 01054940 https://en.herbariumle.ru/?t=occ&id=5815, photos LE LE 01073300 https://en.herbariumle.ru/?t=occ&id=15910, LE 01073302 https://en.herbariumle.ru/?t=occ&id=15912). VIETNAM. Thua Thien Hue Province: Nam Dong District, Thuong Lo Municipality, Cha Mang river basin, around point 16°07’53’’N 107°43’27’’E, primary evergreen broad-leaved lowland forest on very steep hill slopes composed with stratified shale at elev. 400–500 m a.s.l., epiphyte on mossy trees on very steep rocky shady river slope, flowers white, locally very common, 11 April 2007, L. Averyanov, N. S. Khang, A. Averyanova, N.D. Phuong, L. V. Hung, HAL 11101 ( LE LE 01054936 https://en.herbariumle.ru/?t=occ&id=5811, photos LE LE 01073301 https://en.herbariumle. ru/?t=occ&id=15911). VIETNAM. Thua Thien Hue Province: Phu Loc District, Bach Ma National Park, S slope of Bach Ma mt, below Hai Vong Dai peak, around point 16°11’65’’N 107°51’53’’E, at elev. about 1150 m a.s.l., mixed and broad-leaved evergreen secondary closed mountain forest on steep shale/granite slopes and cliffs, epiphyte and lithophyte on shady waterfall cliff, flowers white with green tint, common, 20 April 2003, L. Averyanov, N. T. Vinh, HLF 1172 ( LE LE 01054942 https://en.herbariumle.ru/?t=occ&id=5817, LE 01054943 https://en.herbariumle. ru/?t=occ&id=5818, photos LE LE 01073304 https://en.herbariumle.ru/?t=occ&id=15914). VIETNAM. Thua Thien Hue Province: Phu Loc District, Bach Ma National Park, N slope of Bach Ma mt system, to the N of point 16°11’50’’N 107°50’44’’E, at elev. 600–1000 m a.s.l., mixed and broad-leaved evergreen primary closed wet mt forest with Shorea stellata & Dacrycarpus imbricatus along narrow ridge and on very steep sandstone/shale slopes, epiphyte and lithophyte in shady place on waterfall cliffs, flowers light yellowish-green, locally abundant, 28 April 2003, N. T. Hiep, L. Averyanov, N. T. Vinh et al., HLF 1382 ( LE LE 01054935 https://en.herbariumle.ru/?t=occ&id=5810, LE 01054941 https://en.herbariumle.ru/?t=occ&id=5816, photos LE LE 01073305 https://en.herbariumle.ru/?t=occ&id=15915). VIETNAM. Quang Nam Province: Nam Giang District, Song Thanh Nature Reserve, forest, river bank, epiphytic, 15°33’14’’N 107°24’21’’E, elev. 740 m, 11 May 2019, M. S. Nuraliev 2539 ( LE LE 01058724 https://en.herbariumle. ru/?t=occ&id=9377, LE 01059478 https://en.herbariumle.ru/?t=occ&id=10034; MW MW 0756280 https://depo.msu. ru/open/public/en/item/ MW 0756280). VIETNAM. Gia Lai Province: K’Bang District, K’rong Municipality, Kon Ka Kinh National Park, 27 km NW of K’Bang Town, forest, river bank, epiphytic, 14°19’39’’N 108°26’11’’E, elev. 810 m a.s.l., 13 May 2017, M. S. Nuraliev 1773 ( LE LE 01054911 https://en.herbariumle.ru/?t=occ&id=5787, LE 01054914 https://en.herbariumle.ru/?t=occ&id=5790, photos LE LE 01087666 https://en.herbariumle.ru/?t=occ&id=41969; MW MW 0754803 https://depo.msu.ru/open/public/en/item/ MW 0754803). VIETNAM. Dak Lak Province: Chu Yang Sinh Mountains, June 2015, Nguyen Van Canh, s.n. (photos LE LE 01073303 https://en.herbariumle.ru/?t=occ&id=15913). VIETNAM. Dak Lak Province: Chu Yang Sinh Mountains, 30 November 2015, Nguyen Van Canh, L. Averyanov, T. Maisak, s.n. ( LE LE 01054915 https://en.herbariumle.ru/?t=occ&id=5791). VIETNAM. Dak Lak Province: Krong Bong District, Cu Pui Municipality, elevation from Dak Tour Village to main peak of Chu Yang Sinh mountain system along Dak Tour River ( N slope), primary closed mountain broad-leaved evergreen forest on granite slopes along river canyon at elevation of about 1000 m a.s.l., epiphyte on mossy trees along river in shady places, flowers white, light yellowish, common, 12 May 2000, L. Averyanov, N. T. Hiep, N. Q. Hieu, P. H. Hoang, D.X. Du, N. T. Vinh, VH 6456 ( LE LE 01054954 https://en.herbariumle.ru/?t=occ&id=5829). VIETNAM. Ninh Thuan Province: Ninh Hai District, Vinh Hai Municipality, NEE slopes on Nui Chua mountains to SW of point 11°43’52’’N 109°08’35’’E, at elev. about 600–700 m a.s.l., primary evergreen closed dry forest on rocky mountain slopes composed with granite, lithophyte on shady rocks on rocky stream slope, flowers white, locally common, 28 March 2004, J. Regalado, N. T. Hiep, P. K. Loc, L. Averyanov, N. T. Vinh, P. V. Doan, T. T. An, N. T. Hoi, T. V. Huong, N. V. Su, T. T. T. Trang, H. A. Tuan, HLF 4271 ( LE LE 01054934 https:// en.herbariumle.ru/?t=occ&id=5809, LE 01054944 https://en.herbariumle.ru/?t=occ&id=5819, photos LE LE 01073297 https://en.herbariumle.ru/?t=occ&id=15907, LE 01073298 https://en.herbariumle.ru/?t=occ&id=15908). VIETNAM. Southern Vietnam, sine loc., January 2005, sine coll., herbarium prepared from wild collected cultivated plants on 9 December 2020, L. Averyanov, T. Maisak, AL 1280 ( LE LE 01076995 https://en.herbariumle.ru/?t=occ&id=57026, photos LE LE 01088330 https://en.herbariumle.ru/?t=occ&id=46981, drawing LE LE 01122806 https://en.herbariumle. ru/?t=occ&id=99397).

Figures

FIGURE 16. Appendicula spicata. A. Flowering shoot. B. Flower, front view. C. Flower, side view. D. Flower, front view (lip removed). E. Lip, view from above and from below. F. Lip, sagittal section. Drawn from the specimen Averyanov, T. Maisak, AL1280 by L. Averyanov.

FIGURE 17. Appendicula spicata. A, B. Flowering shoots. C. Inflorescences. D. Apical portion of shoot with inflorescence. E, F. Inflorescences, side view. G. Inflorescence, view from apex. H–J. Flower, half-side, front and side view. K. Column, front view. L. Young fruit.A–C, G: Averyanov, Maisak, AL1280, photos by L. Averyanov; D–F, H–K: Nuraliev 2539, photos by M. Nuraliev. Photo correction and design by M. Nuraliev.