Kirkia

Biogeography and Ecology of Southern Africa

Southern Africa is certainly not a naturally bounded area so that there are several possibilities for delineating it and concepts about its extent. Wellington* discussed the various possibilities for delineation and suggested that one line stands out more clearly and definitely as a physical boundary than any other, namely the South Equatorial Divide, the watershed between the ZaIre, Cuanza and Rufiji Rivers on the one hand and the Z ambezi, Cunene and Rovuma Rivers on the other. This South Equatorial Divide is indeed a major line of separation for some organisms and is also applicable in a certain geographical sense, though it does not possess the slightest significance for many other groups of organisms, ecosystems or geographical and physical features of Africa. The placing of the northern boundary of southern Africa differs in fact strongly per scientific dis cipline and is also influenced by practical considerations regarding the possibilities of scientific work as subordinate to certain political realities and historically grown traditions. This is illustrated, for example, in such works as the Flora of Southern Africa, where the northern boundary of the area is conceived as the northern and eastern political boundaries of South West Africa, South Africa and Swaziland. Botswana, traditionally included in the area covered by the Flora Zambesiaca, thus forms a large wedge in 'Southern Africa'.

Flowering Plants. Eudicots

This volume, the tenth in the series, comprises modern treatments for the families and genera of the eudicot orders Sapindales and Cucurbitales. The circumscription of the orders, families and genera conforms to the most recent systematic studies. The family treatments include descriptions of the families and the genera, genera classification keys, discussions of relationships and data on their morphology, reproductive biology, distribution, ecology and economic importance. Sapindales and Cucurbitales, as understood in this volume, comprise 16 families with 637 genera and roughly 9,240 species. Sapindales include large tropical and southern temperate tree families such as the Anacardiaceae, Sapindaceae (these in the modern circumscription, which includes Aceraceae and Hippocastanaceae), Meliaceae and Rutaceae, which have long been considered to be closely related. Cucurbitales represent a relatively new ordinal concept; apart from some small woody groups, the order contains two large families, Cucurbitaceae and Begoniaceae, which are predominantly, and likely basically, herbaceous. A detailed treatment of the tropical and southern temperate woody family Myrtaceae (itself comprising 142 genera and 6,700 species) is an addendum to the treatment of the Myrtales in Vol. IX of this series.

Svenskt Diplomatarium