The genus <i>Ehretia</i> (Boraginaceae: Ehretioideae) in southern Africa

Abstract

The genus Ehretia P.Browne in southern Africa is revised. Six species and five subspecies of Ehretia are currently rec­ognized in southern Africa, of which E. alba Retief & A.E.van Wyk, E. namibiensis Retief & A.E.van Wyk subsp. namibi­ensis, E. namibiensis subsp. kaokoensis Retief & A.E.van Wyk, E. rigida subsp. silvatica Retief & A.E.van Wyk and E. rigida subsp. nervifolia Retief & A.E.van Wyk are newly described. The genus is widely distributed in the region and occurs in a variety of habitats, ranging from the forests of the Eastern Cape to the hot, arid, semidesert parts of Namibia. Members of Ehretia in southern Africa are predominantly multistemmed shrubs or small trees. Characters of the leaf, the trichome com­plement, inflorescence and corolla are used to distinguish between the different species. A key to the species, distribution maps and illustrations of various micro- and macromorphological as well as palynological features are provided.

Keywords

• Boraginaceae
• <i>Ehretia</i>
• Ehretiaceae
• key
• morphology
• palynology
• pollen
• southern Africa
• taxonomy