Contributions to the systematics of the genus zantedeschia spreng (Araceae)

Abstract

Zantedeschia, a genus of eight species and two subspecies, is endemic to Africa, south of the equator. The genus is popular among plant lovers and horticulturalists world-wide, largely through a multitude of hybrids cultivated as garden and pot plants, and marketed as cut flowers. In this study the taxonomic usefulness of morphology, anatomy, pollination biology and phytogeography is surveyed. Variation in tuber form, lamina shape, spathe shape and colour, staminodes and berry colour were found to be particularly important in separating species. Anatomy, on the other hand, provided few attributes for species differentiation. Post pollination changes are distinct in Z. aethiopica. Patterns of distribution also proved to be useful in confirming the identity of taxa. Based on morphology and distribution pattern, Z. albomaculata subsp. valida is raised to species level as Z. valida. Finally, a taxonomic treatment for the Flora of southern Africa is included