FLORA OF VIETNAM
Orchidaceae
Cleisostoma melanorachis Aver.

Son La Prov., Mai Son Distr., Hat Lot town, around point 21°13′05”N 104°06′44”E.

Secondary evergreen dry open 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 550-650 m a.s.l.

Epiphyte on gnarled trees on top of mountain. Occasional

CPC 1156a/6 21 December 2010
Coll.: L.Averyanov, P.K.Loc, P.V.The, N.T.Vinh.

Fl. under cultivation at 28 Feb. 2011
Flowers odorless; sepals and petals white with purple tint; lip purple-violet with 2 dull yellowish bosses at the base; spur pink-purple; column light purple-violet; operculum light yellowish with brownish-purple medial stripe; pollinia yellow; pedicel and ovary purple-violet; floral bracts and inflorescence axis dark purple, nearly black. L.Averyanov 29 Feb. 2011 Photos.