Oxalis saltusbelli: A new Oxalis (Oxalidaceae) species from the Oorlogskloof Nature Reserve, Nieuwoudtville, South Africa

Abstract

In South Africa, the genus Oxalis includes 200 species inhabiting a wide range of habitats particularly in the winter rainfall areas of the western and southern Cape. Many species are morphologically extremely plastic, which makes species identification and description of new species challenging based solely on morphological criteria. Here we report the discovery of a new species, Oxalis saltusbelli Dreyer & Roets, from the Cape Floristic Region of South Africa. Placement of this taxon within the genus was based on DNA sequence-based analyses of the Internal Transcribed Spacer (ITS) region and morphological comparisons with related species. The new species is currently only known from the Oorlogskloof Nature Reserve. It has sticky bulb tunics, multifoliolate leaves, with variable leaflet shapes ranging from oblong to linear, depending on age, concave petioles and lilac flowers. This study brings the number of Oxalis species in South Africa to 201 and highlights the urgent need for molecular and morphological re-evaluation of all taxa in this morphologically and ecologically diverse plant lineage.