N. Vietnam, prov. Lai Chau, about 50 km downstream along Black river (Song Da), from Lai Chau town (N 22°03′ E 103°09′) to Nam Ma village (distr. Sin Ho). Open shale and limestone rocks on steep slopes of the river at elev. about 220 m. Lithophyte fern on vertical wet shady rocky cliffs. Common.
NTH 2745 24 May 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)