A systematic study of Ruschia Schwantes section Ruschia {Mesembryanthemaceae Fenzl)

Abstract

This systematic revision of Ruschia Schwantes section Ruschia consists of an alpha taxonomic treatment, supplemented by detailed study of the morphology of the leaves, stems, flowers and fruit and Scanning Electron Microscope study of the stigmas and pollen. Species descriptions were compiled usirig 77 morphological characters using the DELTA software package. The delimitation of species was complicated by the variability of some characters and the lack of variation in others. The morphological characters are illustrated through diagrams, line drawings and light and electron micrographs. No single diagnostic character can be used to distinguish between all ten species. Phenetic and cladistic analyses of the data were done. The phenetic analysis was done using the NTSYS software package. For the cladistic analysis the WinCLADA software package was used. Both the phenetic and cladistic analyses support a major division in the section: a group consisting of R. perfoliata, R. odontocalyx and R. rupicola and a second group which consists of R. uncinata, R. ruralis, R. indurata, R. unidens, R. axthelmiana, R. canonotata and R. semidentata. Distribution maps of the species are included, and were compiled using the MAPPIT software package.