New species and taxonomic notes in Ixia (Iridaceae: Crocoideae) from western South Africa

New collections of the southern African genus Ixia (± 98 species) ostensibly belonging to the Western Cape species Ixia cedarmontana prompted a review of the species. I. cedarmontana is reserved for plants from marshy, sandy habitats with white or pale pink flowers and long cylindrical tube up to 25 mm long. Cherry pink-flowered plants from shale band habitats are removed to the new Ixia seracina whereas plants with a shorter, funnel-shaped tube and a pink perianth with yellow cup are described as Ixia arenosa. I. seracina is known from two montane sites in the Cold Bokkeveld and Grootwinterhoek Mtns, south of the range of I. cedarmontana. The range of I. arenosa overlaps that of I. cedarmontana but extends southwards into the Cold Bokkeveld. We also describe the new Ixia macrocarpa from Loeriesfontein in Northern Cape, an acaulescent species with a filiform perianth tube, the filaments inserted at the mouth of the tube and united in a column enclosing the style. We infer an immediate relationship with Ixia acaulis, the only other acaulescent species in the genus. We include distribution maps and illustrations for all new species as well as comments on the conservation status for each species. In addition we report important range extensions for Ixia collina and Ixia robusta, until now known from one or very few localities.