Amphithalea is a genus of flowering plants in the legume family Fabaceae, placed in the subfamily Faboideae and tribe Podalyrieae. It comprises about 41 species, all endemic to the Cape Provinces of South Africa, within the Cape Floristic Region. The genus was first described in 1836 by the German botanists Christian Friedrich Ecklon and Carl Ludwig Philipp Zeyher.
Amphithalea includes small shrubs and subshrubs, many of which were formerly classified under the genus Coelidium. The two genera were merged by A.L. Schutte following a taxonomic re-evaluation published in 1998, which synonymized Coelidium and several other genera into Amphithalea based on morphological evidence. The type species is Amphithalea ericifolia, an ericoid shrub with small heath-like leaves typical of fynbos vegetation. Notable members include Amphithalea fourcadei, Amphithalea imbricata, and the type species itself.
Distribution
Amphithalea is endemic to the Cape Provinces of South Africa, occurring within the Cape Floristic Region at the southern tip of Africa. The genus is restricted to this biodiversity hotspot, with its 41 species distributed across the fynbos and surrounding vegetation types of the Western Cape and Eastern Cape provinces.
Taxonomy
Amphithalea belongs to the tribe Podalyrieae within the subfamily Faboideae (Fabaceae). The genus was described by Ecklon and Zeyher in 1836. A significant taxonomic revision by A.L. Schutte in 1998 re-evaluated the generic boundaries and synonymized Coelidium (described by Vogel ex Walpers in 1840) into Amphithalea, along with several other genera: Cryphianthia, Epistemum, Heudusa, Ingenhoussia, and Lathriogyna. As a result, many species formerly placed in Coelidium were transferred to Amphithalea with authorities citing "(Benth.) A.L. Schutte" or similar combinations. GBIF records approximately 47 accepted species. Wikipedia, citing Plants of the World Online, lists 41 species.
History
The genus Amphithalea was established in 1836 by Christian Friedrich Ecklon and Carl Ludwig Philipp Zeyher, German botanists who extensively collected and described the flora of South Africa. For over 150 years, it coexisted with the related genus Coelidium, described in 1840. The modern circumscription was set by A.L. Schutte's 1998 revision in the journal Taxon, which merged Coelidium and several lesser-known genera into Amphithalea, nearly doubling the number of recognized species and establishing the current taxonomic framework.
