Description from Flora of China
Climbing shrubs or lianas, rarely small trees. Leaves alternate, leathery or nearly so, rarely papery, conspicuously reticulate, base asymmetric, margin entire or toothed. Flowers small, bisexual, 5-merous, few in fascicles or in shortly pedunculate cymes, or in terminal or axillary, cymose panicles. Sepals 5, triangular, adaxially medially keeled. Petals obovate-orbicular, apex emarginate, rarely absent. Disk thick, fleshy, pentagonous. Ovary globose, immersed in disk, 2-loculed, with 1 ovule per locule; styles 2-fid. Fruit a 1-seeded, indehiscent samara, 1/3-1/2 of base surrounded by persistent calyx tube, apex with longitudinally elongating oblong wing, with relict styles; endocarp globose, thin, woody, 1-loculed, 1-seeded. Seeds without endosperm; cotyledon thick.
Ventilago zhengdei G. S. Fan (J. Nanjing Forest. Univ. 28(1): 107. 2004), described from Yunnan, could not be treated here because no material was seen by the authors.
About 40 species: Old World tropics; six species (two endemic) in China.