Bulbophyllum malleolabrum Carr (1932: 24)

Dang, Minh Quan, Averyanov, Leonid V., Maisak, Tatiana V., Tran, Thi Thuy Nhan, Nguyen, Van Canh, Wook, Um Sung, Nguyen, Quoc Bao, Truong, Quang Tam & Truong, Ba Vuong, 2024, Bulbophyllum section Macrocaulia (Orchidaceae) in Vietnam, Phytotaxa 677 (3), pp. 265-277 : 267-269

2. Bulbophyllum malleolabrum Carr (1932: 24) , Holttum (1964: 434), Seidenfaden & Wood (1992: 512), Vermeulen et al. (2015: 549), Averyanov et al. (2024: 12).

( Fig. 1B )

= B. lingii M.Z.Huang, G.S.Yang & J.M.Yin in Huang et al. (2020: 185). Type:— CHINA. Hainan: Lingshui City, Mount Diaoluoshan, tree trunks, 900 m, 29 May 2013, Huang 13052901 (holotype ATCH).

Habitat and phenology: —Creeping epiphyte. Primary and secondary evergreen broad-leaved montane forests on granite. Flowers in May–June.

Distribution: — Vietnam (provinces Lao Cai and Son La). S China (Hainan), Peninsular Malaysia, Borneo, Sulawesi.

Conservation assessment: — Bulbophyllum malleolabrum is recorded from three sites in Vietnam, two in Lao Cai Province and one in Son La Province and is facing threats of poaching. Accordingly, three sites are considered as three locations. In Lao Cai, the species is found in disturbed forest areas, with one of the locations experiencing local collection, which is threatening to the wild population of this species. The status of the species in Son La cannot be assessed due to inaccessibility of the habitat. At both places there is threat of continuing decline in the quality of the habitat too. The EOO and AOO is estimated as 188 and 12 km 2 respectively. Accordingly the species can be assessed as Endangered [EN B1ab(iii,v)+B2ab(iii,v)]. The species is known to be distributed in Borneo, Malaya and Sulawesi ( POWO 2024) and hence, the chances of immigration of propagules from populations outside Vietnam is meek. Accordingly, the preliminary assessment is retained for the final regional assessment in Vietnam.

Note: — Bulbophyllum malleolabrum looks similar to B. catenarium but differs by the subglobose apex glabrous or finely papillose (vs. globose apex strongly warty in B. catenarium ).

Specimen examined: — VIETNAM, Lao Cai Province: Bat Xat District, Bat Xat Nature Reserve, 4 km SSE of Y Ty Village, disturbed forest, stream bank, epiphytic, 1900 m a.s.l., 2019, Nuraliev M.S. 2680 (photo LE01058754 http:// en.herbariumle.ru/?t=occ&id=9407). VIETNAM, Lao Cai province, Bat Xat District, forest around Y Ty Commune, 2024, herbarium and photos prepared from cultivated in Da Lat City, Lam Dong Province, Averyanov L.V., Nguyen Van Canh, T. Maisak, AL3183 (photo LE 01276219 https://en.herbariumle.ru/?t=occ&id=229821). VIETNAM, Son La Province: Chu Xuan Canh , s.n., 25 November 2010, herbarium and photos prepared from cultivated plants in May–June 2012, L. Averyanov s.n. (photo LE01055790 http://en.herbariumle.ru/?t=occ&id=7687, LE LE01087157 http:// en.herbariumle.ru/?t=occ&id=18681).

3. Bulbophyllum catenarium Ridley (1894: 235) , Seidenfaden & Wood (1992: 512), Ho (2000: 860), Averyanov & Averyanova (2003: 14), Chen & Vermeulen (2009: 415), Vermeulen et al. (2015: 550).

( Fig. 1C )

Lectotype (designated by Vermeulen 1991: 171):— Malaysia, Sabah, Kinabalu, Havilland 1164 (photo K000829842 !).

Habitat and phenology: —Creeping branch and canopy epiphyte. Humid broad-leaved forests. Flowers in March.

Distribution: — Vietnam (provinces Lam Dong, Gia Lai, and Kon Tum). China, Peninsular Malaysia.

Conservation assessment: — Bulbophyllum catenarium is known from four sites in Vietnam which fall within designated protected areas. However, there are threats of habitat destruction as a result of deforestation and illegal logging. This species is also known to be collected from wild for trade for horticultural purposes, further contributing to population decline. Accordingly, four sites are treated at four locations. In Vietnam, the extent of occurrence (EOO) is 21471 km ² and an area of occupancy (AOO) is 16 km ². Based on above information, the species can be assessed as Endangered [EN B2ab(v)]. The species is however known to be distributed in Borneo, China South-Central, Malaysia and Vienam ( POWO 2024). Accordingly, globally the preliminary assessment is downlisted to Vulnerable [VU B2ab(v)].

Species examined: — VIETNAM, Gia Lai Province:Kon Plong, Mang Canh, 1000–1200 m, epiphyte on tree, at the forest border, flowers yellow, 27 May 1985, Averyanov, LX-VN 2258 (photo LE LE01055262, https://en.herbariumle. ru/?t=occ&id=6947, LE LE01073478, https://en.herbariumle.ru/?t=occ&id=17616). VIETNAM, Lam Dong Province: Bao Loc City Area, old secondary dry evergreen broad-leaved and mixed (with Pinus kesiya ) submontane forest on granite at elevation of about 1000 m a.s.l. on top of hill, creeping epiphyte on old tree bark, occasional, 27 October 2019, L. Averyanov, Nguyen Van Canh, T. Maisak, AL 1204.6 (photo LE LE01067561 https://en.herbariumle.ru/?t=occ&id=13800, LE LE01070249 https://en.herbariumle.ru/?t=occ&id=13540). VIETNAM, Lam Dong Province: forest around Da Lat City, 17 March 2021, Truong Ba Vuong, Ngo Quang Dang, BV1210 (VNM VNM00070774). VIETNAM, Lam Dong Province: forest around Da Lat City, 3 December 2020, Truong Ba Vuong, Nghiem Xuan Son, BV967 (VNM VNM00070768).

Figures

FIGURE 1. Flowers of species of Bulbophyllum section Macrocaulia in the flora of Vietnam. A. Bulbophyllum ovalifolium (specimen BV378 VNM00070770). B. B. malleolabrum (AL3183 LE01255063). C. B. catenarium (BV1210 VNM00070774). D. B. moniliforme (BV s.n. LE 01087378. E. B. ignevenosum (BV1794 VNM 00063960). F. B. physocoryphum (BV1041 VNM00070762). Photos by Truong Ba Vuong and L. Averyanov.