A revision of the South African species of Holothrix Rich. ex Lindl. (Orchidaceae)

Immelman, Kathleen Leonore

A revision of the South African species of Holothrix Rich. ex Lindl. (Orchidaceae)

Master Thesis

1979

Publisher

University of Cape Town

Department

Department of Biological Sciences

Faculty

Faculty of Science

Abstract

The genus Holothrix in South Africa is desc.ribe.d and its taxonomic history discussed. The results of using a computer to draw up a key and a dendrogram of the species are briefly discussed, as are some of the problems experienced. Various morphological characters are evaluated for their usefulness or otherwise in distinguishing species, and a key is provided. Where applicable, problems commonly encountered when attempting to identify the species are mentioned, and those characters pointed out which will distinguish the species. Details of biological interest are mentioned. Each species is illustrated by a drawing of sepal, petal and lip. Those species available in liquid preservative have the whole flower drawn as well, while those where a live plant could be obtained are illustrated in full, with a drawing of the whole plant, leaves, column and pollinia. In those cases where a range in shape, as opposed to size, is experienced, drawings are presented to illustrate this range. A detailed map of each species is presented, using the 1° gridsquare system, and also a table of the ranges of rainfall and altitude within the range of each species.