N. Viet Nam. Ha Giang Province, Quang Ba District, Bat dai Son. Primary forest on limestone with Biota sp., Fraxinus, Quercus, Pseudotsuga, Acer and Taxus dominants along ridge and below peak at elev. 1100-1200 m (about 23°07′N 105°02′E). In shady palces. Petals white with green spots at base of lip. Occasional and widespread. DKH 5098 5 April 2000