N. Vietnam, Prov. Cao Bang, distr. Tra Linh, municipalite Quoc Toan, vicinity of Thang Heng and Lung Tao villages near Thang Heng lake. Broadleaved evergreen closed primary forest on steep slopes and bluffs of limestone mesas and ridges at 600-650 m alt. Epiphyte on high trees. Tepals dirty yellowish with dirty purple tint, lip deep purple. Not common. VH 4867 25-27.05.1997 International Botanical Expedition of the U.S.A. National Geographic Society (grant No 5803-96)