Climber with up to 5 m long, herbaceous or softly woody shoots, a perennial, tuberous rootstock, and dioecious sex system. The leaves are simple, petiolate, the blade entire or 3-5-lobed, ovate, with cordate base, and acute apex. The tendrils are apically bifid. The flowers are small, the male inflorescences are axillary panicles, the female flowers in thyrses or monochasia with 3-6 flowers. The receptacle-tube is saucer-shaped with five triangular, 0.5-1 mm long sepals. The corolla is regular and consists of five triangular, c. 1 mm long, free, greenish-yellow petals. The single stamen is central with two, horizontal, semicircular thecae, which form a split ring and release tricolporate, striate, small pollen (polar axis 29-34 µm, equatorial axis 24-27 µm, (Khunwasi 1998)). The ovary is compressed with one apical placenta and one pendent ovule. The three styles are short with bifid stigmata. The fruit is an elliptic compressed samara, to 55 by 22 mm, indehiscent, ripening brown. The solitary seed is elliptic and compressed, to 11 mm long with pale brown, slightly rough testa.
The three species are found in lowland evergreen forest, deciduous forest and bushland, two in East and South tropical Africa and one endemic in Madagascar.
Phylogenetically, the genus groups with the New world genera Pteropepon and Sicydium from which it split about 41 million years ago (Schaefer et al. 2009).
Cyclantheropsis madagascariensis Keraudren, Fl. Madag. 185: 164. 1966.
Cyclantheropsis occidentalis Gilg & Mildbr., Bot. Jahrb. Syst. 58: 241. 1923.
Cyclantheropsis parviflora (Cogn.) Harms, Bot. Jahrb. Syst. 23: 169. 1896.
Khunwasi, C. 1998. Palynology of the Cucurbitaceae. Doctoral Dissertation Naturwiss. Fak., University of Innsbruck.
Schaefer, H., Heibl, C., and S.S. Renner. 2009. Gourds afloat: a dated phylogeny reveals an Asian origin of the gourd family (Cucurbitaceae) and numerous oversea dispersal events. Proceedings of the Royal Society B 276: 843-851.