A new species of Sterculia (Malvaceae) from Vietnam.

A new species of Sterculia from Vietnam - S.konchurangensis - is described, illustrated, and compared with the similar S.lanceolata. S.konchurangensis differs from S.lanceolata by the length of the petiole (7.0-9.5 vs. 25-35 mm), shape of the leaf blade (obovate or elliptic vs. elliptic, lanceolate or elliptic-lanceolate), length of the leaf blade (6-8 vs. 9-20 cm), and length of the calyx lobe (11-12.5 vs. 4-6 mm). A diagnostic key of the 22 Sterculia species occurring in Vietnam is also provided.

Isotremaputalengense, a new species of Aristolochiaceae from northern Vietnam and two new combinations in Isotrema.

Isotremaputalengense Luu, Q.B.Nguyen & H.C.Nguyen is described as a new species from northern Vietnam. It looks most morphologically like I.wardianum but is distinguishable by a combination of different leafy and floral characters. Morphological comparison between the new plant and closest species is provided. In addition, combinations of two recently described Aristolochia species are made, namely Isotremavuquangense (T.V.Do) Luu, Q.B.Nguyen & H.C.Nguyen and Isotremayachangense (B.G.Huang, Yan Liu & Y.S.Huang) Luu, Q.B.Nguyen & H.C.Nguyen.