Description from Flora of China
Vines woody, deciduous, climbing by aerial roots. Leaves opposite, 1-pinnately compound; leaflets serrate. Inflorescences short paniculate, terminal, or flowers in clusters. Calyx campanulate, subleathery, irregularly 5-lobed. Corolla red or orange-red, campanulate-funnelform, slightly bilabiate; lobes spreading, semirounded. Stamens 4, didynamous, curved, included. Ovary 2-locular, base surrounded by a large disc. Capsule dehiscing loculicidally. Seeds numerous, compressed, membranous, with semitransparent wings.
Two species: one in North America, another in Japan and China.