FLORA OF VIETNAM. Orchidaceae. Biermannia calcarata Aver. Thanh Hoa Prov., Thuong Xuan Distr., Van Xuan Municipality, Hang Cao village, Xuan Lien Natural Reserve. Remnants of primary and secondary broad-leaved evergreen forest on highly eroded rocky limestone hills at elevation 100-200 m a.s.l. around point 19°50'47.2"N 105°14'42.7"E. Epiphyte on mossy trees on very steep rocky shady slope near mountain top. Common. 8 November 2013 CPC 6896. Coll.: L.Averyanov, N.T.Hiep, N.S.Khang, N.D.Thang, L.D.Qui