Carruanthus is a small genus of just two species of succulent flowering plants in the ice plant family, Aizoaceae (order Caryophyllales). It belongs to subfamily Ruschioideae, tribe Ruschieae, and was established by the German botanist Gustav Schwantes. The genus is endemic to South Africa, where it occurs in the Eastern and Western Cape Provinces.
Plants are compact and caespitose (forming dense clumps or tufts). The leaves are the defining feature: Carruanthus ringens bears prominently toothed leaves reminiscent of the related genus Faucaria, but the two are distinguished by Carruanthus's stalked fruit capsules. Its sister species, Carruanthus peersii, has much less toothed foliage. Both species produce bright yellow daisy-like flowers during the spring growing season. In habitat, C. ringens grows in full sun exposures while C. peersii prefers shaded sites. Though unusual in cultivation, the genus is easily propagated from both seed and stem cuttings.
Distribution
Carruanthus is endemic to South Africa, occurring in the south-central and southern Cape Provinces (both the Eastern and Western Cape). The genus has a restricted range within the Greater Cape Floristic Region.
Ecology
The two species occupy different light niches within their shared range. Carruanthus ringens is a full-sun plant, while Carruanthus peersii grows in shaded sites. Both are leaf succulents adapted to the semi-arid conditions of the Cape region.
Cultivation
Carruanthus species are unusual in succulent collections. They are easily propagated from both seed and stem cuttings. Bright yellow flowers appear in spring. C. ringens should be grown in full sun; C. peersii benefits from partial shade. As Cape succulents, they require well-draining soil and a dry rest period.
Taxonomy
Carruanthus was published by Gustav Schwantes as (Schwantes) Schwantes, belonging to subfamily Ruschioideae, tribe Ruschieae within Aizoaceae. The genus Tischleria Schwantes is treated as a synonym. Only two species are accepted: C. peersii L.Bolus and C. ringens (L.) Boom. The genus is distinguished from the similar Faucaria by its stalked (rather than sessile) fruit capsules.
