The bryofloristic elements of southern Africa

Abstract

A TWINSPAN classification divides the moss flora of southern Africa (South Africa, Namibia, Botswana, Swaziland, and Lesotho) into two main bryofloristic elements: (1) the Xerophytic (south-western) element mainly distributed in the winter rainfall and semi-arid to arid, temperate areas of southern Africa, and (2) the Mesophytic (subtropical) element distributed in more stable, subtropical habitats of the northern, eastern and southern parts of southern Africa. The Xerophytic element is dominated by acrocarpous mosses, including the ephemerals, while the Mesophytic element contains most of the pleurocarpous mosses. The main Xerophytic element is subdivided into the Eastern Highlands and Cape Elements while the Mesophytic element consists of the Afromontane Grassland and Afromontane Forest Elements. The Afromontane Forest Element is the largest bryofloristic element and contains the most southern African moss endemics. The four bryofloristic elements are subdivided into eight subelements: the Eastern Highlands Element into the Mont Aux Sources and Widespread Subelements, the Cape Element into the West Coast and Boland Subelements, the Afromontane Grassland Element into the Disjunct Cape Peninsula and Drakensberg Subelements, and the Afromontane Forest Element into the Widespread Afromontane and Tropical Afromontane Subelements. Many of the bryofloristic elements and distribution centres correspond with phytogeographical elements and centres described for the seed plants of southern Africa. The Afromontane area in the south-western Cape is identified as a bryogeographical hotspot.

Keywords:

• Floristic elements
• Hotspot
• Moss flora
• Numerical classification
• Plant biogeography
• TWINSPAN
• Southern Africa

The facilities and funding provided by the Acting Curator of the National Herbarium in Pretoria, Ms E. Rampho, are gratefully acknowledged. Professional assistance by Ms Hester Steyn and Ms Daleen Maree is much appreciated.