N. Vietnam, Prov. Thai Nguyen, distr. Dai Tu, vicinities of Tam Dao town, NE macroslope of Tam Dao ridge at 950-1000 m alt. (N 21°27′ E 105°38′). Closed wet evergreen broadleaved primary forest on very steep mt slope. Terrestrial and epilitic fern on wet shadow steep slopes and rocky bluffs. Not rare. VH 4999 31.05.1997 International Botanical Expedition of the U.S.A. National Geographic Society (grant No 5803-96)