N. Vietnam, prov. Quang Ninh, distr. Hon Gai, Halong bay, Dan Go island. Secondary broadleaved evergreen forest on steep limestone slopes and vertical bluffs on elevations 0-100 m above s.l. Epiphyte at the mossy base of large trees on top of ridge. Flowers dirty yellow, lip with dull purple marks. Not common.
NTH 2635 12 May 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)