A taxonomic revision of the genus Ancylobothrys (Apocynaceae, Plumerioidae) in South Africa, including the description of a new geoxylic species

Abstract

In South Africa, Ancylobothrys Pierre was last revised in 1963, although the taxa were maintained within the genus Landolphia P. Beauv. Later authors separated Ancylobothrys from Landolphia citing the tendril-like inflorescence and the softly pubescent fruit of Ancylobothrys as two of the most obvious characters separating these genera. A geoxylic form related to Ancylobothrys petersiana (Klotzsch) Pierre occurs in deep sandy soils of the Maputaland woody grassland in northern KwaZulu-Natal and is endemic to the Maputaland Centre of Endemism. This study shows that there is sufficient morphological distinction for this taxon to be considered a separate species, Ancylobothrys pumilus K. Balkwill & R.A. Reddy. The separation of A. pumilus from A. petersiana has necessitated a revision of the genus in South Africa. A key and descriptions to the South African species of Ancylobothrys are provided.