Leguminosae of Ethiopia

Abstract

There has long been a deeply felt need for a “Flora of Ethiopia” . After preparatory work within A. E. T. F. A. T. (Association pour I'Etude Taxonomique de la Flore d'Afrique Tropicale) during the 1970's, a joint project between the Faculty of Science, Addis Ababa University and the Institute of Systematic Botany, Uppsala University has recently started with support from SAREC (Swedish Agency for Research Cooperation with Developing Countries). Being one of the largest and economically most important families in the country, Leguminosae was selected for a pilot project and it is hoped that the present work will serve as a model for the Flora. The aim of the present paper is to give a concise account of all species of the family Leguminosae known to occur in Ethiopia and to provide a means of identifying them. Leguminosae, with its 613 species, is the second largest family in the country after the slightly larger Gramineae. Comprising approximately 10% of the total number of species in Ethiopia, the family includes many plants used for food, forage, pasture improvement, charcoal production, timber and ornament. Although this work is based on studies of virtually all herbarium material available, supplemented by fieldwork in various parts of Ethiopia, it is by no means to be considered complete. Large areas in Ethiopia are still very inadequately known and by continued botanical exploration additional species will no doubt be discovered. 1 hope, however, that this volume will increase the interest in the Ethiopian flora and stimulate to further collect;ng and taxonomic research, and also that it will prove useful to all those interested in applied botany in any of its forms. The account of subfam. Caesalpinioideae has been written jointly with R. Polhill, Kew and that of subfam. Mimosoideae with A. Hunde, Uppsala, except for Acacia for which A. Hunde is alone responsible. Botanical exploration The botanical exploration of Ethiopia started earlier than in almost any other tropical African country. Already in 1769—1772 Ethiopia was visited by the Scottish traveller and naturalist J. Bruce who brought back seeds which were grown in various European botanical gardens and also made engravings and descriptions of many Ethiopian plants only 24 of which were published (Bruce 1790). Several legumes have been based on Bruce’s material, among them the mysterious, never recollected Bauhinia farek Desv. During the 19th century very important collections were made by the German W. G. Schimper (in Ethiopia from 1837 until his death in 1878) and the Frenchmen R. Quartin Dillon (in Ethiopia from 1838 until his death in 1840) and A. Petit (in Ethiopia from 1838 until his death in 1843). Their collections formed the basis of A. Richard’s “Tentamen Florae Abyssinicae" (1847-51) which recorded all the about 1700 species then known from the country. Owing to this comparatively early exploration numerous tropical African plants were first described from Ethiopia and knowledge of the Ethiopian flora is therefore important for the understanding of taxonomy and nomenclature of the tropical African flora as a whole. This early botanical activity was concentrated in the North and Central parts of the country, and the East and South parts were not visited by botanists until near the turn of the century. During the first half of this century most botanical work was done by Italians, mainly in Eritrea and other northern regions. Important revisional work has been published in Italy since 1953 in ‘‘Adumbratio Florae Aethiopicae” (appearing in Webbia). From 1953 to 1961 the Englishman H. F. Mooney made extensive collections in Ethiopia which now form the nucleus of the National Herbarium in Addis Abeba. A recent milestone in the botanical history of the country is Cufodontis’ “Enumeratio Plantarum Aethiopiae Spermatophyta” (1953—1972) in which all published information on the flora of Ethiopia, Somalia and Djibouti is collated into a checklist. A revised version of this checklist (covering also Sudan and Socotra) is now being prepared within A. E. T. F. A. T. As regards Leguminosae, 19 cultivated legume crops were treated by Westphal (1974), and a guide to pasture legumes, concentrating mainly upon species occurring in the central highlands, was produced by Froman (1974). For a more exhaustive list of collectors in the area see Cufodontis (1962). Stearn (1982) gives further details about early collectors. Cufodontis (1951) and Gillett (1972) give very valuable information on Schimper’s travels and collecting localities in Ethiopia.