Biosystematic Study of the African and Madagascan Rubiaceae

Biosystematic studies on the Rubiaceae have a long tradition at the Institute of Botany in Vienna. Within this family the Anthospermeae, and especially its African and Madagascan members, are of particular interest because of several aspects in their evolution: I) Perfection of anemophily within an otherwise nearly exclusively zoophilous family; 2) transitions from hermaphrodity to polygamy and finally dioecy; 3) differentiation from large and long-lived shrubs to short-lived herbs; 4) adaptive radiation from humid to seasonally dry, fire-exposed and xeric habitats. However, morphological diversity linked to sexual differentia- tion, modificatory plasticity, and eco-geographical polymorphism have for a long time hampered our understanding of the relationships among these African Anthospermeae. Thus, it was imperative to put special emphasis on field observations and to carry out a variety of experiments with cultivated plants in addition to the analysis of an enormous herbarium material. The author, for this reason, carried out extensive field work, often under very adverse conditions, and covered most African countries from Ethiopia to Southern Africa and twice visited Madagascar. In this way a multitude of data was accumulated on the group in respect to germination and growth form, vegetative and reproductive morphology, anatomy and biology, embryology, karyology, crossing relationships, phytochemistry, distribu- tion and ecology, etc.