Bulbophyllum nodosum, (Rolfe 1895: 35) Smith (1912: 26)

Dang, Minh Quan, Averyanov, Leonid V., Dang, Van Son, Maisak, Tatiana, Bui, Van Huong, Tu, Bao Ngan & Truong, Ba Vuong, 2022, Bulbophyllum section Rhytionanthos (Orchidaceae) in Vietnam with description of new taxa and new national record, Phytotaxa 530 (3), pp. 257-270 : 265

3. B. nodosum ( Rolfe 1895: 35) Smith (1912: 26) , Seidenfaden (1973: 73), Pearce & Cribb (2002: 479) ( Fig 1 ).

≡ Cirrhopetalum nodosum Rolfe (1895: 35) . Type:— INDIA, Nilgiri , O’Brien s.n. ( K000829967 photo!, http://specimens.kew.org/ herbarium/ K000829967 ) .

≡ Rhytionanthos nodosum ( Rolfe 1895: 35) Garay, Hamer & Siegerist (1994: 639) .

Habitat and phenology:—Creeping epiphyte on large trees in dry forests at elevation of about 1000 m a.s.l.

Distribution:— Vietnam (Son La Province). India.

Notes:—The species is very close to B. helenae , but can be easily distinguished by the clavate hairs on pedicel, ovary, and abaxial surface of sepals, as well as in having nodular swellings on the thick rhizome. Our discovery represent new national record of this species in the flora of Vietnam.

Studied specimens:— INDIA, Nilghiri Hills , s.coll., s.n. ( K000829967 photo!, type of B. nodosum ) . INDIA, Nilghiri Hills , s.coll., s.n. ( K000829965 photo! http://specimens.kew.org/herbarium/ K000829965 , K000829966 photo! http://specimens.kew.org/herbarium/ K000829966 , K000829968 photos! http://specimens.kew.org/herbarium/ K000829968 ) . VIETNAM, Dien Bien Province, Tua Chua District, Sin Chai Municipality , around point 22°03’38”N 103°19’56”E, primary humid evergreen broad-leaved forest on very steep rocky slopes and on tops of remnant mountain composed with highly eroded marble-like solid crystalline limestone at elevation of 1350–1500 m a.s.l., epiphyte, occasional, 14 December 2010, L. Averyanov et al., CPC 982 a/3 ( LE01068417 http://en.herbariumle. ru/?t=occ&id=15085, LE01055568 http://en.herbariumle.ru/?t=occ&id=7316, LE01087022 http://en.herbariumle. ru/?t=occ&id=18117 photos) . VIETNAM, herbarium specimen prepared from plants cultivated in private garden in Ho Chi Minh City, originated from Son La Province, Thuan Chau District , 28 August 2021, Truong Ba Vuong BV 1260 ( VNM00069916 , LE01122925 http://en.herbariumle.ru/?t=occ&id=107046 photos), BV 1261 ( VNM00069917 ) , 15 September 2020, Truong Ba Vuong, Ngo Quang Dang, BV 1298 ( VNM00069922 ) .

Figures

FIGURE 1. Bulbophyllum nodosum (Rolfe) J.J.Sm. A. Flowering plant; B. Leaf apex, adaxial and abaxial side. C. Inflorescences. D. Inflorescence rachis. E. Floral bract. F. Flowers, side and back views. G. Pedicel, ovary and flower, side view. H. Median sepal, adaxial and abaxial side. I. Median sepal margin. J. Lateral sepals, adaxial and abaxial side. K. Lateral sepal margin. L. Petal, adaxial and abaxial side. M. Lip, views from different sides. N. Pedicel, ovary and column with sepals removed (above), and with all tepals removed (below). O. Surface of ovary and column foot base. P. Column, petals and lip, view from above. Q. Column, frontal and side views. R. Anther cap, views from different sides. S. Pollinia. Photos by Truong Ba Vuong, correction and design by L. Averyanov and T. Maisak.