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 broad-leaved primary forest on very steep mt slope. Terrestrial herb with leaves up to 1.5 m lg on steep shadow rocky wet slope. Flowers yellow. Very common. VH 5047 31.05.1997 International Botanical Expedition of the U.S.A. National Geographic Society (grant No 5803-96)