A new species of Sartidia (Graminae), endemic to ultramafic soils

Abstract

A species of Sartidia De Winter, first collected by P.J. Muller in 1972 in the Cythna Letty Nature Reserve in Mpumalanga, does not match existing material of Sartidia, a genus comprising four species. The new species, S. dewinteri J. Munday & L. Fish, is most similar to S. jucunda (Schweick.) De Winter but differs in the leaf sheath colour, lower leaf blade surface texture, spikelet length and upper glume length. It differs also from all other species in the genus in the shape and branching of the inflorescence, the relative length of the lateral awns to the median awn, lemma body surface texture, callus shape and hair arrangement, palea shape and distribution. Sartidia dewinteri differs anatomically from S. angolensis and S. vanderystii in that the stereome strands in the leaf blades project partly or almost completely into the first order vascular bundles rather than not at all, and from S. jucunda by having 3 rather than 5 first order vascular bundles in the leaf. Sartidia dewinteri is known only from ultramafic soils of the Barberton Greenstone Belt and is thus considered a serpentine endemic. The IUCN conservation status of S. dewinteri is considered to be Lower Risk — least concern, although some of its ultramafic habitat is under threat from afforestation and the after effects of mining.