N. Vietnam, Prov. Cao Bang, distr. Tra Linh, municipalite Quoc Toan, vicinity of Thang Heng and Lung Tao villages near Thang Heng lake. Remnant closed evergreen primary broadleaved forest in alluvial valley bottom between limestone ridges and mesas near karst lake at 500 m alt. Tree up to 20 m hg. Ripe cyconia dirty purple-green. Not rare. Sometimes codominante of 1 forest stratum in alluvial valley bottom and limestone ridge slopes up to 600-650 m alt. VH 4847 25-27.05.1997 International Botanical Expedition of the U.S.A. National Geographic Society (grant No 5803-96)