Bulbophyllum basiflorum M.K.Li, J.P.Deng & Y.Luo, Taiwania

J., Tsering, K., Chowlu & Kumar, P., 2024, Bulbophyllum basiflorum (Orchidaceae) from India - further extension of a recently described species in the East Himalaya Biodiversity Hotspot, Rheedea 34 (1), pp. 61-64 : 62-64

Bulbophyllum basiflorum M.K.Li, J.P.Deng & Y.Luo, Taiwania 68(2): 143–147. 2023. Type: CHINA, Xizang, Medog county, Dexing village , N 95°14’26.49”, E 29°14’21.92”, 1159 m, epiphyte on tree trunks in evergreen broad-leaved forest, 06.05.2020, M.K. Li 2020233 (holo, [ HITBC 0083564 ]; para [ HITBC 0083565 , XZE 016070 ]). Figs. 1 & 2

Rhizomes creeping, 1–1.5 mm thick. Pseudobulbs cylindric to narrowly ovoid, 1–2 × 0.5–0.8 cm, longitudinally grooved, placed 1.5–5.0 cm apart on rhizome. Leaf 1, oblong-ovate, borne on the apex of the pseudobulb, 1.5–4.0 × 0.8–1.3 cm, shortly petiolate, apex minutely two lobed or retuse. Scape erect or stout, arising from base of pseudobulbs or from nodes of rhizome, shorter than pseudobulbs, 4–10 mm long, peduncle erect, with tubular sheaths; racemose, usually 2-flowered or sometimes 3-flowered. Flowers 5–7 mm across, not so widely open, light yellowish; floral bract ovate-triangular, 4–5 × 3–4 mm long, acuminate, longer than pedicel and ovary, light brown when dry; pedicel plus ovary 2.5–3.0 mm long. Dorsal sepal narrowly lanceolate, twisted, 6–8 × 1.4–1.5 mm, acuminate at apex; lateral sepals narrowly lanceolate, 8–10 × 1.4–1.5 mm, acuminate, adnate to base of column foot; petals ovate, 1.6–2.1 × 0.9–1.1 mm, acute at apex; lip oblong or tongue shaped, slightly recurved, 1.5–2.5 × 0.9–1.1 mm, entire, pale yellowish, fleshy, with two ridges along a median furrow, obtuse at apex. Column 1–1.4 mm long, stout, stelidia subulate, c. 0.5 mm long, projecting forwards; column foot 0.3– 0.5 mm long, curved upwards; anther cap sub globose, 0.4–0.5 mm long, rounded at apex. Pollinia 4, in two pairs, c. 3 mm long.

Flowering & fruiting: Flowering from April to May; fruiting not observed.

Habitat: Found growing on branches of medium sized trees in sub-tropical areas at 1100 to 1270 m elevation.

Distribution: China, and now India .

Specimens examined: INDIA , Arunachal Pradesh, East Kameng, Sachung, N 27°33’27”, E 92°46’48”; J. Tsering 50180 (Orchid Herbarium Tipi); West Kameng , Sessa Orchid Sanctuary, Sessa, N 27°6’14”, E 92°31’30”; J. Tsering 50186, 50187 (Orchid Herbarium Tipi) .

Conservation status: Bulbophyllum basiflorum was originally described as a Data Deficient (DD) species fromChina(Li etal.,2023).Thisspeciesisnowknown from three different sites, one in Xizang, China with around 20 mature individuals, and two in Arunachal Pradesh, India with 100 and 80 mature individuals. The total number of known mature individuals for this species is 200. The Area of Occupancy (AOO) is estimated as 12 km 2 and Extend of Occurrence (EOO) is estimated as 719 km 2. All the three known sites are located near human settlement areas and hence, at least in India , anthropogenic threats are suspectedowing to which, a decline in number of mature individuals is projected. Therefore, this species can now be provisionally assessed as Endangered [EN B1ab(iii,v)+ B2ab(iii,v); C2a(i); D] following the guidelines for the IUCN Red List Categories and Criteria ( IUCN, 2022). However, further studies on population size, distribution and population trends and threats are encouraged and it should be reassessed if more information becomes available.

Notes: The specimens of B. basiflorum from India exhibited few minor variations from the type description,such as an inflorescence with 1–3 flowers (vs. 1–2-flowered in the original description), leaves broader, up to 1.3 cm wide (vs. narrower, up to 0.7 cm wide) and broader pseudobulbs, up to 0.8 mm wide (vs. narrower, up to 0.6 mm wide). However, we consider this as natural variation in the species across its distributional range.

Figures

Fig. 1. Bulbophyllum basiflorum M.K.Li, J.P.Deng & Y.Luo: Plants in Sessa Orchid Nursery.

Fig. 2. Bulbophyllum basiflorum M.K.Li, J.P.Deng & Y.Luo: a–c. Habit; d. Floral bract; e–i. Flower from different angles; j. Dissected flower (dorsal sepal, lateral sepals and petals); k–l. Column with lip, ovary and pedicel; m–n. Column with ovary and pedicel; o–p. Lip; q. Anther cap with pollinia; r. Anther cap; s. Pollinia (from J. Tsering 50186; photos by J. Tsering).