A new species of Cyrtanthus (Amaryllidaceae: Cyrtantheae) from the Agulhas Plain, Western Cape, South Africa

Abstract

Described is a new species of Cyrtanthus within the monogeneric tribe Cyrtantheae (Amaryllidaceae: Amaryllidoideae) from the low-lying Agulhas Plain, Western Cape, South Africa. Known from the Nuwejaars Wetlands area, Cyrtanthus novus-annus occupies habitats transitional between Elim Ferricrete Fynbos and Central Rûens Shale Renosterveld. The erect, mostly solitary-flowered inflorescence has a nearly sessile, funnel-shaped flower in common with C. guthrieae, which occurs on the mountains close to Bredasdorp in acidic soils of Overberg Sandstone Fynbos. The two species differ in the size, colouring, and markings of the flowers and in their flowering times. Their morphological similarity and the close proximity of their habitats suggest that C. novus-annus and C. guthrieae constitute an example of edaphically differentiated sister taxa, a pattern found in several other endemics of the region, as well as in the sister pair Brunsvigia elandsmontana and B. marginata (tribe Amaryllideae) from contrasting habitats in Swartland lowland alluvium and the abutting sandstone mountains, respectively.