Bulbophyllum sect. Desmosanthes

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 : 8-12

Bulbophyllum sect. Desmosanthes

Bulbophyllum medusae (Lindl.) Reichenbach (1861: 262) , Holttum (1964: 409), Seidenfaden & Smitinand (1961: 361), Backer & Bakhuizen van den Brink (1968: 381), Seidenfaden (1973a: 166, 1979: 172), Vermeulen (1991: 109), Seidenfaden & Wood (1992: 468), Wood & Cribb (1994: 300), Coode et al. (1996: 381), Comber (2001: 797), O’Byrne (2001: 31), Vermeulen et al. (2015: 149), Díaz-Morales et al. (2019: 735), Lindsay et al. (2022: 532).

( Fig. 4 )

≡ Cirrhopetalum medusae Lindley (1842 : tab. 12).

Type: — SINGAPORE. Sine loc., H. Cuming s.n. (holotype K, fide Díaz-Morales et al. 2019: 735).

Habitat and phenology in Vietnam: —Creeping epiphyte. Lowland broad-leaved evergreen forests. Very rare. Flowers in April–May.

Distribution: — Vietnam: Quang Nam Province (sine loc.). S Thailand, Peninsular Malaysia, Singapore, Sumatra, Borneo, possibly the Philippines.

Conservation status in Vietnam: —In accordance with the scarcity of available data, we estimate the national conservation status of Bulbophyllum medusae as Data Deficient (DD). Its conservation status outside Vietnam has never been evaluated.

Notes: —An uncertainty exists in literature regarding the typification of this species. The protologue of Cirrhopetalum medusae ( Lindley 1842) states this species to be native to Singapore, from where it was obtained by Messrs. Loddiges. Díaz-Morales et al. (2019) provided a discussion of origin of the type material and concluded that it has likely been sent to Loddiges & Sons Nursery by Hugh Cuming. At the same time, Wood & Cribb (1994) indicated the type as “Borneo, Lobb s.n.”, which was reproduced by Vermeulen (1991) and Vermeulen et al. (2015). This view, however, is in contradiction with the protologue. We therefore follow Díaz-Morales et al. (2019) in typification of B. medusae .

Bulbophyllum medusae is reported here as a new record for the flora of Vietnam. The discovery of this species in Vietnam essentially expands its mainland distribution area in eastern direction. The nearest earlier known locations of this species are in Peninsular Thailand ( Seidenfaden 1973a, 1979, Seidenfaden & Wood 1992, O’Byrne 2001, Díaz-Morales et al. 2019). Bulbophyllum medusae differs from a very close species B. vaginatum ( Lindley 1830: 59) Reichenbach (1861: 261) in narrowly triangular acuminate petals with entire margins (vs. petals oblong, obtuse, ciliate throughout the margins; see Holttum 1964, Seidenfaden 1973a, 1979, Comber 1990, 2001, Vermeulen 1991, Seidenfaden &Wood 1992, O’Byrne 2001, Vermeulen et al. 2015). Bulbophyllum vaginatum is distributed sympatrically with B. medusae over most of their distribution across the Malay Peninsula and Greater Sunda Islands, but has not yet been recorded in Vietnam. Similarly to some specimens of B. vaginatum , the Vietnamese specimen of B. medusae is characterized by pure white flowers, whereas in the rest of its distribution area B. medusae often has sepals and petals finely speckled with purple. In B. vaginatum , pale yellow flower coloration also occurs frequently.

Studied specimen:— VIETNAM. Quang Nam Province: sine loc., 22 April 2023, Truong Ba Vuong, BV 1715 (VNM 00063996, photos LE LE01124198 https://en.herbariumle.ru/?t=occ&id=170350).

Bulbophyllum sutepense (Rolfe ex Downie) Seidenfaden & Smitinand (1961: 366) , Kerr (1969: 197), Seidenfaden (1971: 339, 1972a: 111, 1973a: 169, 1975a: 20, 1979: 79, 1992: 297), Chen et al. (1999: 44, 2009: 412), Schuiteman et al. (2008: 271), Xu et al. (2010: 408), Zhou et al. (2016: 21), Ormerod et al. (2021: 50), Jin et al. (2023: 451).

( Fig. 5 )

≡ Cirrhopetalum sutepense Rolfe ex Downie (1925: 376) . Gagnepain in Gagnepain & Guillaumin (1934: 292).

Type: — THAILAND. Chiang Mai Province: Doi Sutep, 2000–2500 ft [600–750 m], on trees in deciduous jungle, flowers yellow, 4 June 1909, A. F. G. Kerr 162 (lectotype K, first-step lectotype designated by Seidenfaden (1971: 339), second-step lectotype designated here: K K 000597356 photo!, isolectotype K K 000597355 photo!).

Habitat and phenology in Vietnam: —Clustering epiphyte. Primary and old secondary evergreen broad-leaved and mixed forests on granite at elevation of 1000–1500 m a.s.1. Rare. Flowers in May–June.

Distribution: — Vietnam: provinces Kon Tum (Dak Glei District), Gia Lai (K’Bang District) and Lam Dong (Da Lat City area). E Myanmar, SW China, N Thailand, Laos.

Conservation status in Vietnam: —Available data on natural populations of Bulbophyllum sutepense in Vietnam are very scarce. Three populations are known, and the areas inhabited by at least two of them are influenced by selective logging. In particular, the logging occurs in the Kon Ka Kinh National Park, despite its status of a legally protected territory. Based on these conditions, we estimate the national conservation status of the species as Near Threatened (NT). Jin et al. (2023) assessed the status of this species as Least Concern (LC) but have not provided any details or reasons for their decision.

Notes: —The protologue of Cirrhopetalum sutepense ( Downie 1925) cites a single gathering, Kerr 162, without indication of a place of its deposition. Seidenfaden (1971) indicated the type specimen to be housed at K, which appears to fulfill the conditions of lectotypification (Art. 7.11 of ICN, Turland et al. 2018). However, we have found that there are two specimens of the collection Kerr 162 deposited in K (K000597355 and K000597356) and thus Seidenfaden’s choice (1971) was the first-step for lectotypification (Art. 9.17). We have selected the specimen at K with barcode K000597356 as the lectotype in the second-step following Arts. 9.3 and 9.11 because it contains flowers and bears a label with a handwritten identification by Rolfe, unlike the other one. The specimen K000597355 is isolectotype.

Seidenfaden (1973a, 1979) additionally cited a specimen at P belonging to the type gathering. We have found a single relevant sheet deposited in P (P00362002), which, however, does not bear any collector’s number on the original label but has a curatorial note “prob. no 162 ”. Most importantly, it has a different date of collection, i.e. 21 June 1914. One more sheet with identical collection information and a collector’s number as “(162)” was found at K (K000597357). These two sheets are not parts of the type material of this species, because they belong to another gathering.

Bulbophyllum sutepense is reported here as a new record for the flora of Vietnam. In its habit and floral morphology, Bulbophyllum sutepense is somewhat similar to B. corallinum Tixier & Guillaumin in Guillaumin (1963: 204; see also Seidenfaden 1979, Chen et al. 1999, 2009, Jin et al. 2023) and B. echinulus Seidenfaden (1982: 193 ; see also Liu & Gao 2016, Averyanov et al. 2021, Jin et al. 2023) that have similar distribution. However, it distinctly differs from both of them in long acuminate lateral sepals twice as long as the median sepal (vs. lateral sepals acute or shortly acuminate, only slightly longer than the median sepal).

Studied specimens:— VIETNAM. Kon Tum Province: Dak Glei, 23 May 2023, Truong Ba Vuong BV 1734 (VNM 00063985). VIETNAM. Gia Lai Province: K’Bang District, K’rong Municipality, Kon Ka Kinh National Park, 26 May 2017, Nuraliev M.S., Kuznetsov A.N., Kuznetsova S.P. 1881 (LE LE01055288 https://en.herbariumle. ru/?t=occ&id=6972, photos LE LE01087692 https://en.herbariumle.ru/?t=occ&id=42904). VIETNAM. Lam Dong Province: Da Lat City area, 2021, Nguyen Van Canh, AL1552 (LE LE01169133 https://en.herbariumle.ru/?t=occ&id=141006).

Figures

FIGURE 4. Bulbophyllum medusae. A. Flowering plants. B. Flattened plants. C. Inflorescence. D. Floral bracts, adaxial and abaxial side. E. Flower, side view. F. Median sepal, adaxial and abaxial side. G. Lateral sepals, adaxial and abaxial side. H. Petals, adaxial and abaxial side. I. Lip, views from different sides. J. Ovary, lateral sepal, column, column foot and lip, side view. K. Ovary, column, column foot and lip, side view. L. Ovary, column and column foot, side, half-side and front view. Photos by Truong Ba Vuong from living plant prior to the preparation of the voucher herbarium specimen Truong Ba Vuong, BV 1715. Photo correction and design by L.Averyanov and T. Maisak.

FIGURE 5. Bulbophyllum sutepense. A. Flowering plant. B. Inflorescence. C. Flower, half-side view. D. Flower and flower bud. E. Flower, view from below. F. Flower with pollinaria and anther cap removed. G, H. Flower with one lateral sepal removed, side view. I. Central part of flower, view from below. J. Median sepal, petal and column, view from below. Photos by M. Nuraliev from living plant prior to the preparation of the voucher herbarium specimen M. Nuraliev et al., NUR1881.