Clematicissus is a small genus of weak-climbing flowering plants in the grape family, Vitaceae (order Vitales). The genus comprises approximately six species distributed across two disjunct regions: South America and Australia, reflecting a biogeographic pattern shared by several other Vitaceae genera.
Plants are tendril-bearing climbers or scramblers, with tendrils that are simple or 2-branched. The leaves are palmately compound, typically with 3 to 7 leaflets (most commonly 5), the central leaflet distinctly larger than the lateral ones; leaf surfaces range from glabrous to pubescent, and margins may be entire to deeply serrated. Flowers are small and borne in leaf-opposed cymes that may be congested or lax. The calyx is shortly lobed; petals number 4 or 5 and are free, yellowish-green or reddish in colour. The floral disc is concave to spreading and fused to the base of the ovary. The ovary is 2-locular with 2 ovules per loculus; the style is conical with a small, shortly capitate stigma. Fruits are berries containing 1 to 4 seeds.
The Australian species were formerly included in the larger genus Cissus, but molecular and morphological studies led to their recognition within Clematicissus. Two species are endemic to Australia, with one (C. opaca) occurring in New South Wales. South American species include C. striata, a vigorous climber native to Chile and Argentina sometimes cultivated as an ornamental. The genus name reflects its relationship to both Clematis and Cissus, two other climbing genera.
Etymology
The name Clematicissus combines elements of Clematis (from Greek klema, a vine-shoot or tendril) and Cissus (from Greek kissos, ivy), reflecting the genus's climbing habit and its relationship to both genera. The combination name alludes to the fact that Australian members were previously classified within Cissus.
Distribution
Clematicissus has a disjunct native range spanning South America and Australia. Two species are endemic to Australia, with one (C. opaca) restricted to New South Wales; South American species such as C. striata are native to temperate regions including Chile and Argentina. The genus contains approximately six species worldwide.
Taxonomy Notes
Clematicissus belongs to the family Vitaceae (order Vitales). Australian members of the genus were historically placed in Cissus and were later segregated into Clematicissus following revised treatments; the NSW species C. opaca is treated per Jackes, Flora of Australia online (2023). GBIF recognises the genus as accepted with no published authorship on record.
