A Revision of the Genus Echinops (Compositae-Cardueae) in Tropical Africa

Abstract

The most recent revision of tropical African species of Echinops was that made by Jeffrey (1968) who provided a key to the 20 species then known. Since then a number of new species have been described and there has also been some relegation of taxa (Lisowski 1989, Mesfin 1990, Mesfin & Berhanu 1990). The species found in Ethiopia were revised in 1990 (Mesfin & Berhanu 1990). In this work, notes on the phytogeography of the genus in Africa were also presented. The only descriptions then available for many of the remaining species were the original ones. It was thus thought prudent to thoroughly revise the African members of the genus and provide English descriptions for all of them. The African species have also been the subject of chemical studies (Berhanu et al. 1991). The investigation of the roots of nine species of Echinops from Ethiopia revealed the presence of 20 polyacetylenic thiophenes, sesquiterpenes and triterpenes. In this work the presence of three groups of species was indicated and a call made for studies on those species with tuberous roots from other parts of tropical Africa. The morphological study is based on herbarium specimens kept at BM, BR, EA, ETH, K, LE, MO, NY, P, UPS, US, W and WU, and also on field observations in Ethiopia and Kenya. All types studied are indicated (!).