In this paper, a new family for the flora of Vietnam - Tetracentraceae is found in Hoang Lien National Park, Lao Cai province. It includes one species only - Tetracentron chinense Oliv. This is a primitive relic family of Teriate flora and belong to Himalaya phytogeographical element. This family together with Trochodendraceae (the second monotype family) belong to the ordo: Trochodendrales of the subclass: Hamamalididae of the Dicotyledons. The presence of this family in Hoang Lien is an important evidence that Hoang Lien mountain might be lied in a “possible centre” of Angiosperms as Takhtajan (1970) suggeted. However, He also indicated that the Trochodendrales is a ordo linked with both Magnoliidae and Hamamelididae
Nguyen Nghia Thin
Faculty of Biology, Hanoi College of Science, HNU