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Notes on African Plants. Apocynaceae: Transfer of Schizoglossum umbelluliferum to Stenostelma, and its neotypification (Asclepiadoideae)
Stenostelma umbelluliferum is an enigmatic plant that has elicited much attention in recent years. Initially thought to be extinct, its rediscovery in an urban area created turmoil in both conservation management and urban development. Taxonomic and field investigations were conducted over a number of years to gain a more comprehensive understanding of the species, and each new batch of information lead to conservation status changes. A re-assessment of the conservation status is presented, based on the most recent evidence of its distribution, threats and population dynamics.
The first record of Polygala westii (Polygalaceae) from the North-West Province (South Africa) is reported on here. The species is very rare and has previously only been collected in two separate gatherings. This species is characterised by having bracts and bracteoles caducous, the anterior sepals connate at least as much as half of their length and seeds pubescent and carunculate. It grows in a habitat that are severely impacted by agriculture and mining. A preliminary assessment of its conservation status is given. A key to the South African species in the subsection (Tetrasepalae) to which P. westii belong is provided. The aim of this paper is to highlight the species in order to stimulate the lookout for more material of this species.
The large and unnatural grouping 'Schizoglossum E. Meyer' is reviewed. Schizoglossum sensu stricto comprises 12 species endemic to southern Africa; these are keyed out, described, mapped and illustrated. The account includes two new species, four new subspecies and seven new combinations at subspecific rank. Most of the species formerly regarded as members of Schizoglossum are excluded. Miraglossum Kupicha is described; it comprises seven species endemic to southern Africa, including two new species and five transferred from Schizoglossum. These are keyed out, described, mapped and illustrated. Aspidoglossum E. Meyer is distributed throughout southern and tropical Africa, with its centre of diversity in Natal and the Transvaal. Four sections are recognised, each including both southern and tropical members. The genus comprises 34 species: three original, six new to science and 25 with basionyms in Schizoglossum; of the latter, 21 names are newly combined here. The species are keyed out, described and illustrated. 58 names in Schizoglossum are left without generic position as a result of the three revisions above. Over half of these names are here tentatively allocated to Glossostelma Schltr., Pachycarpus E. Meyer or Stenostelma Schltr.; others are distributed among a miscellany of genera; and the remainder are listed but unassigned to genus.