Bulbophyllum manhdatii, 2021

Pham, Phuoc Dien, Averyanov, Leonid V., Dang, Van Son, Nguyen, Dinh Hiep, Maisak, Tatiana, Truong, Quang Tam, Dang, Minh Quan & Truong, Ba Vuong, 2021, A new species and new record of Bulbophyllum (Orchidaceae) from Vietnam, Phytotaxa 522 (1), pp. 68-72 : 69-72

B. manhdatii Vuong, Aver., V.S.Dang & Q.T.Truong sp. nov. ( Figure 1 )

Type:— VIETNAM, Lam Dong Province, Langbiang , 16 April 1984, Leonid Averyanov LX-VN 1663 (holotype LE 01057657 http:// en.herbariumle.ru/?t=occ&id=7835, photos LE01087248 http://en.herbariumle.ru/?t=occ&id=18963) .

Paratypes:— VIETNAM, Lam Dong Province, Lac Duong District, forest around Khanh Le Pass , 6 April 2020, Truong Ba Vuong, Truong Quang Tam, Dang Van Son, Ngo Quang Dang, Hoang Manh Dat, BV 576 ( VNM00032284 ). VIETNAM, Lam Dong Province, Lac Duong District, forest around Khanh Le Pass , 5 May 2020, Truong Ba Vuong, Truong Quang Tam, Dang Van Son, Ngo Quang Dang, BV 647 ( VNM00032285 ) .

Etymology:—The plant name honors Mr. Hoang Manh Dat who found the specimens and provided them for investigation.

Description:— Miniature twig epiphyte. Pseudobulbs globular to broadly ovoid, erect, 1–1.5 cm tall, connected by woody, stout rhizome, 1–1.5 mm in diameter, 3 mm apart. Leaves shortly petiolate; petiole 1–2 mm long; leaf blade oblong, 3–3.7 cm long, 1–1.2 cm wide, adaxially green, light green on abaxial surface, apex rounded, retuse. Inflorescence arising from the base of pseudobulb, slender, umbellate, with 4–6 flowers opening simultaneously; peduncle 2–2.2 cm long, slightly curved, covered by 3–4 dark brownish to almost black tubular overlapping sheaths at base and 1–2 pale brown tubular bract above; rachis erect 2.5–2.7 cm long; floral bracts ca. 2.5 mm long, slightly curved, acute; pedicel and ovary 6–7 mm long, pedicel slender, curved. Flowers uniformly yellow, lip occasionally somewhat purplish at base. Dorsal sepal ca. 4 mm long, 1 mm wide, concave, somewhat attenuate, directed forward, cucullate, truncate to slightly retuse; lateral sepals ovate-narrowly ovate, broadening at the base, ca. 10 mm long, 1.5–2 mm wide (at base), apical part attenuate, twisted at the base, connate along upper margin, lower margin free at base, and connate in apical portion, forming acute tube. Petals broadly ovate, slightly oblique, 3–3.3 mm long, 2 mm wide, apex rounded. Lip simple, ca. 2 mm long, 1 mm wide at base, movably attached to column foot by short white ribbon-like appendage, slightly curved, margin upright erected, apex mucronate, adaxial surface smooth, without keels. Column erect, ca. 1 mm tall, oblique; column foot up-curved, ca. 1.5 mm long; stelidia ca. 0.5 mm long, erect, slightly incurved, upper margin with small teeth; lower margin with inconspicuous wings; stigma rectangular; rostellum insignificant; anther cap helmet-shaped, yellow, brown and finely warty at apex; pollinia 4, half-obovate, in two pairs. Fruits not seen.

Habitat and phenology:—Clustering branch epiphyte in primary broad-leaved forest at elevations 1500–2000 m a.s.l. Flowers in April–May.

Distribution:— Vietnam (Lam Dong Province). Endemic.

Additional specimens studied: — MYANMAR, Mon State: Mawlamyine District, 1860, Parish220 (K000829092, K000829181, photo!) as B. pumilio .

Notes:—The newly described species looks superficially close to B. pumilio but differs in a series of morphological characters presented in the Table.

The information of B. pum ilio is based on Parish & Reichenbach (1874: 153), Hooker (1890: 778, as Cirrhopetalum pumilio ) and Seidenfaden (1979).

Figures

FIGURE 1. Bulbophyllum manhdatii Vuong, Aver., V.S.Dang & Q.T.Truong; A. Plant habit; B. Flowering plants; C. Leaf apex; D. Inflorescences; E. Flower bract; F. Flowers at different views; G. Dorsal sepal; H. Lateral sepals; I. Petals; J. Lip at different views; K. Pedicel, ovary, and column, side view; L. Column, frontal view; M. Anther cap at different views; N. Pollinaria. Photos by Ba Vuong Truong, correction and design by L. Averyanov and T. Maisak.