The Cheilanthes hirta complex and allied species (Adiantaceae/Pteri­daceae) in southern Africa

Abstract

The very variable complex of plants until now ascribed to Cheilanthes hirta Swartz, together with some derived or allied species, is investigated. The type of the species as established by N. C. Anthony (1984), is accepted. Three new varieties are distinguished: Cheilanthes hirta Swartz var. brevipilosa W. & N. Jacobsen, var. inferacampestris W. & N.Jacobsen and var. nemorosa W. & N. Jacobsen. One new form of Cheilanthes hirta var. brevipilosa W. & N. Jacobsen is recognized: forma waterbergensis W. & N. Jacobsen. Var.  laxa Kunze (1836) is given the new status of forma:  Chei­lanthes hirta var. brevipilosa W. & N. Jacobsen forma laxa (Kunze) W. & N. Jacobsen. Three allied species are discussed and included in the key to all taxa mentioned. Taxa are described and information given includes notes on distribution and ecology. Special attention is paid to spore morphology. Most taxa are illustrated by a habit photo, and all by line drawings and scanning electron micrographs (SEM) of the spores. Possible evolutionary conclusions, particularly on the nature of the spores and on frond dimensions in relation to geographical distribution and climate are discussed.