Quang Binh Prov., Minh Hoa Distr., Thuong Hoa Comm., Ban On Vill., Pa Nun Valley, 17°40′22″N, 105°58′22″E, 250 m.
In rather open places of vertical cliffs under heavily logged primary evergreen broad-leaved forests on foot of limestone mts. Lithophyte, up to 0.3 m tall. Occasionally common.