Description: Weak to woody climbers, tendrils (1–)2–3(–8)-branched, sometimes apices with adhesive discs.
Leaves pedately (4–)5(–9)-foliolate or trifoliolate; leaflet margins usually serrate.
Cymes leaf-opposed or pseudoaxillary, rarely axillary, mostly long-peduncled. Flowers bisexual, 4-merous. Calyx almost truncate. Petals free. Disc cupular, 4-lobed, fused to base of ovary. Ovary 2-locular; 2 ovules in each loculus; style conical; stigma small.
Berries 1–4-seeded.
Distribution and occurrence: World: 16 species, Tropical, sub-tropical and temperate Asia to Australasia including the Pacific Islands. Australia: 7 species (5 species endemic), W.A., N.T., Qld, N.S.W.
Previously included uner a broader concept of Cayratia, but differs from that genus by lacking a distinct membrane covering the ventral infolds in the seeds.
Text by R. L. Barrett, January 2025
Taxon concept: G. Parmar et al., (2021) Phylogeny, character evolution and taxonomic revision of Causonis, a segregate genus from Cayratia (Vitaceae). Taxon 70 (6) • December 2021: 1188–1218. https://doi.org/10.1002/tax.12562
| | Key to the species | |
| 1 | Leaflets deeply toothed, ovate to elliptic, less than 4 cm wide | Causonis clematidea |
| Leaflets shallowly crenate, obovate to elliptic, 3–6 cm wide | Causonis eurynema |
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