FLORA OF VIETNAM. Fam. Orchidaceae. Anoectochilus calcareus Aver. N. Vietnam, prov. Cao Bang, distr. Nguyen Binh, municipality Ca Thanh,. vicinities of Ta Phinh village (N 22°44' E 105°50'). Primary open. semideciduous mixed mossy forest (with Pseudotsuga brevifolia, Tsuga. chinensis and Pinus kwangtungensis) along tops of remnant karst. limestone ridge at 1350-1400 m elev. Terrestrial herb on shady very. steep slopes and vertical bluffs. Leaves velvety deep black-brown with. silver-white nerves. Rare. No CBL 1583 19 April 1999. International Botanical Expedition of the U.S.A. National Geographic. Society (grant No 6300-98). . Collectors: P.K.Loc, P.H.Hoang, Averyanov L.