Abstract

Abstract

Detailed investigations of the genera Anthospermum (39 species; widely distributed in Africa S of the Sahara and Madagascar), Nenax (11 species; S Africa), Galopina (4 species; SE Africa) and Carpacoce (7 species; S Africa: SW Cape Floristic Region) are presented which are based on extensive field work, the observation of plants grown in the greenhouse and the study of fixed and dried material in the laboratory. These investigations include growth form analyses and notes on the influence of fire and browsing on habit and growth form; detailed data on stem and leaf, flower, fruit and seed morphology and anatomy and surface micromorphology; analyses of inflorescences; embryological and karyological data and pollen measurements; phytochemical information. Numerous data on the reproductive biology are presented: The secondary anemophily of the genera is described in detail; information on the sex forms of individual plants, and on the sex distributions and sex ratios within populations and species is given; the evolution of dioecy, and the secondary sex characters and the sex dimorphism of dioecious taxa is discussed. Evidence for the presence of self-compatibility and of auto- and geitonogamy of taxa, gathered in greenhouse experiments, is presented; the occurrence of parthenocarpic fruits is reported; no conclusive evidence for the occasionally presumed presence of apomicts within Anthospermum could be found. Experimental proof for the formation of viable hybrids between taxa, as well as a list of putative hybrids is given. Information on the dispersal of the diaspores, their morphological nature, and data on their germination are included. The differential regeneration behavior of taxa after a field fire is pointed out (plants killed by fire and regenerating from seed, vs. plants resprouting from the base).