Bulbophyllum phanquyetii Vuong, Aver. & V.S.Dang, 2022

Dang, Minh Quan, V. Averyanov, Leonid, Dang, Van Son, Maisak, Tatiana, Bui, Van Huong, Tu, Bao Ngan, Nguyen, Van Canh & Truong, Ba Vuong, 2022, A new species, Bulbophyllum phanquyetii and a new national record of B. tianguii (Orchidaceae) from the limestone area of northern Vietnam, Phytotaxa 566 (2), pp. 227-232 : 228-230

Bulbophyllum phanquyetii Vuong, Aver. & V.S.Dang sp. nov. ( Fig. 1 )

Type:— VIETNAM. Herbarium specimen is prepared from plant cultivated in private Phan Trong Quyet garden in Lam Dong Province on 21 March 2022 by Truong Ba Vuong, Bui Van Huong, Dang Van Son, Phan Trong Quyet, BV 1349 (holotype: VNM 00069948 , analytical photos: LE 01123075 https://en.herbariumle.ru/?t=occ&id=132346), originated from Lai Chau Province, Sin Ho District, Xa De Phin Commune .

Etymology:—The species name honors Mr. Phan Trong Quyet, who cultivated the plant and provided material for the description and type specimen preparation.

Description:—Branched epiphyte. Pseudobulbs 1-leaved, yellowish-green, ovoid to narrowly ovoid, 3–3.5 cm high, young pseudobulbs outside with fibrous sheath remnants and 2 thin brown narrowly elliptic bracts, 1.4–1.6 cm long, ca. 9 mm wide, old pseudobulbs clearly 4-angles, distant on 1–2.7 cm on creeping brown rhizome ca. 4 mm in diameter covered by brown to dark brown bracts. Leaves petiolate; petiole 1–1.3 cm long; leaf blade oblong-lanceolate, slightly arching, grassy green adaxially, pale green abaxially, 6–18.5 cm long, 2.9–3.5 cm wide, apex rounded, slightly retuse. Inflorescence erect; scape from the base of pseudobulbs, erect, 10–11 cm long, yellowish-green with many small purple streaks and marks, at base with 2 overlapping tubular bracts, above with a single tubular bract, ca. 1 cm long, apex obtuse to subacute; rachis very short, ca. 1.5 mm long, with 6 flowers in subumbellate raceme; floral bracts narrowly ovate, 3–8 mm long, acute to shortly acuminate; pedicel and ovary ca. 2 cm long, pedicel greenishyellow, with many small purple marks, ovary green, sparely verruculose. Flowers opening simultaneously, with light unpleasant smell; sepals and petals pale yellow, with many small red lines; lip adaxially purple, with many dark purple spots in the middle, abaxially almost white with many purple dots; column pale yellow with many small redpurple dots. Median sepal broadly ovate to almost circular, 7–8 mm long, 6–6.5 mm wide, concave, apex rounded, mucronate, forward directed, adaxially verruculose in apical half. Lateral sepals obliquely triangular, 1.5–1.6 cm long, 5–6 mm wide, acute, adaxially densely verruculose in apical half and sparely verruculose near the base; twisted at middle; upper margin connate in middle part, free at base and apex; lower margin free. Petals oblique, narrowly ovate to ovate, 5–6 mm long, 3–4 mm wide, apex truncate with small seta, adaxially in apical half densely verruculose. Lip simple, fleshy, slightly recurved, 6–7 mm long, 2–2.5 mm wide, apex truncate or rounded, adaxially sparsely verruculose, glossy, shallowly grooved; abaxially with 2 low keels. Column short and stout, 2–3 mm tall, on sides with low half round wings; column foot ca. 5 mm long, upcurved; stelidia triangular, ca. 1 mm long, somewhat oblique, pointing forward, apex blunt; stigma concave, narrowly obovate, ca. 1.5 mm long; anther cap yellow, rectangular, ca. 1.2 mm long and wide, glossy in middle, frontal margin ciliate; pollinaria 2, each with 2 unequal half-globular pollinia. Fruits not seen.

Habitat and phenology:—Branch epiphyte in broad-leaved evergreen montane forest at elevation of 1400 m a.s.l. Flowers in March–April.

Distribution:—Known from the type locality only.

Proposed conservation status:—According to presently available data, the new species is very rare and found only at one site. More field studies are necessary for its conservation assessment. In view of lack of current data and in accordance with IUCN criteria ( IUCN, 2019), the species should be assessed as “Data Deficient” (DD).

Notes:—The new species belongs to the group of similar species including B. chyrmangensis , B. guttulatum , B. putaoense , B. salweenensis , and B. umbellatum . The detailed morphological comparison of these species and our plant is presented on Table 1 .

According to the concept of Vermeulen et al. (2014), all mentioned species belong to B. sect. Brachyantha characterized by subumbellate inflorescence and commonly entire margin of sepals and petals. At the same time, B. chyrmanensis has somewhat isolated position in this group having erose or dentate margin of median sepal and petals. According to this character, this species should be rather placed to B. sect. Cirrhopetaloides than Brachyantha . In the other hands the other morphological features show similarity to the B. umbellatum group, which belongs to B. sect. Brachyantha . As the result, this species in its morphology demonstrates obviously intermediate position between sections Cirrhopetaloides and Brachyantha .

Plant data based on Seidenfaden (1973), Chen & Vermeulen (2009), Verma et al. (2015), Zhou & Jin (2015), and Liu et al. (2017).

Additional specimens examined: Bulbophyllum umbellatum : — VIETNAM, plant cultivated in Ho Chi Minh City, originated from Lam Dong Province, 31 December, 2018, Truong Ba Vuong, BV 537 ( VNM) ; VIETNAM, Lam Dong Province, 21 January , 2019, Truong Ba Vuong, Ngo Quang Dang BV 538 ( VNM) ; VIETNAM, Lam Dong Province, Lac Duong District , 1997, Averyanov & Nguyen Quoc Binh, VH 3838 ( LE 01057984 , https://en.herbariumle. ru/?t=occ&id=8484) ; VIETNAM, Lam Dong Province, Lac Duong District , 1997, Averyanov, Nguyen Quoc Binh, Nong Van Duy, Phan Ke Loc, VH 2771 ( LE 01057983 , https://en.herbariumle.ru/?t=occ&id=8483) ; VIETNAM, Dak Lak Province, Chu Yang Sin Mt., 2011, Petrov , A., s.n. ( LE 01057977 , https://en.herbariumle.ru/?t=occ&id=8478) ; VIETNAM, Ha Giang Province, Quan Ba District, Bat Dai Son Mountains , 2019, Averyanov et al., VR 321 ( LE 01048452 , https://en.herbariumle.ru/?t=occ&id=1842). Bulbophyllum guttulatum :— LAOS, Vientiane Province, Pa Chao Mountain , 2017, Averyanov et al. LA-VN 1743, ( LE 01087488 , https://en.herbariumle.ru/?t=occ&id=40533) ; INDIA, Sikkim Himalaya , 1892, R. Pantling, 53 (MNHN-P-P00348039, http://coldb.mnhn.fr/catalognumber/mnhn/ p/p00348039) ;— INDIA, Darjeeling W. Griffith , 5180 (MNHN-P-P00348038, http://coldb.mnhn.fr/catalognumber/ mnhn/p/p00348038) ; INDIA. Sikkim Himalaya , 1899, R. Pantling, 53 ( L.1484588, https://data.biodiversitydata. nl/naturalis/specimen/ L.1484588) ; NEPAL, 1819, N. Wallich , s.n. (isotype, BM000516909 , https://data.nhm.ac.uk/ object/c860a835-66fc-452c-a09e-fbac1b9ae651) .

Figures

FIGURE 1. Bulbophyllum phanquyetii Vuong, Aver. & V.S.Dang. A. Flowering plant. B. Pseudobulbs and pseudobulb bracts. C. Leaf apex. D. Floral bract, adaxial and abaxial side. E. Inflorescences. F. Flowers, side view. G. Pedicel, ovary and flower, side view. H. Flower, back view. I. Median sepal, adaxial and abaxial surface with magnified surface near the margin. J. Lateral sepal, adaxial and abaxial surface with magnified surface near the margin. K. Petal, adaxial and abaxial surface with magnified surface near the margin. L. Lip, views from different sides. M. Column and lip, side view. N. Pedicel, ovary and column, side view. O. Column apex, views from different sides. P.Anther cap, frontal view and view from back. Q. Pollinaria. Photos by Truong Ba Vuong (type specimen), design by Truong Ba Vuong, L. Averyanov, and T. Maisak.