A taxonomic revision of Gymnodiscus (Asteraceae: Senecioneae: Othonninae), a Greater Cape Floristic Region endemic

• Gymnodiscus is revised.
• Gymnodiscus capillaris var. latifolius is not recognised at any taxonomic rank.
• Gymnodiscus orbicularifolius Sch. Bip. is a new synonym of G. capillaris.
• Both species are described and fully illustrated.

The South African genus Gymnodiscus Less. (Senecioneae: Othonninae) is distinguished from other genera in subtribe Othonninae by its annual habit and lack of pappus in the disc florets. We recognise two species of Gymnodiscus, differing in leaf morphology, number of involucral bracts and florets, shape of the ray florets, and cypsela vestiture. A comprehensive taxonomic treatment is presented, including descriptions, complete nomenclature and typification, illustrations and geographical distribution. Gymnodiscus orbicularifolius Sch. Bip. is treated as a synonym of Gymnodiscus capillaris L.f.