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 and epilitic sedge up to 2 m hg on wet open steep rocky slopes and vertical bluffs. Very common. Usual dominant of forb forest stratum, especially in open places at 1000 m alt. VH 5051 31.05.1997 International Botanical Expedition of the U.S.A. National Geographic Society (grant No 5803-96)