PREFACE 



THE flora of Africa being now comparatively well known, the author 

 of the present work considered the time opportune to present to the 

 public an analytical key for determining in an easy way the generic 

 name of every phanerogamous plant growing wild, whether indigenous or 

 naturalized, or cultivated upon a large scale within the geographical limits of 

 Africa including the islands. 



The names and limits of the genera and families adopted in this work are 

 those accepted in ENGLER & PRANTL'S "Die natürlichen Pflanzenfamihen," 

 the most recent work containing the description of all genera of flowering 

 plants, and its supplement" Genera Siphonogamarum " by DALLA TORRE & 

 HARMS. 



As the present work is intended for the use not only of botanists, but also 

 of colonists and travellers in Africa, who take an interest in botany, I have used, 

 wherever it was possible, as distinctive characters, those which are visible to 

 the naked eye in a plant in flower, being careful, however, not to deviate too 

 much from the natural system. 



Besides the diagnostic characters of the genera, I have also indicated the 

 approximative number of the species described to the end of the year 1910, 

 their geographical distribution, their uses, and their more important synonyms. 



As to the terms used in indicating the geographical distribution of African 

 plants, " North Africa " (including North-west- and North-east Africa) 

 means all northern extratropical Africa, " South Africa " (including South- 

 west- and South-east Africa) southern extratropical Africa, " tropical Africa " 

 Africa within the tropics, including all islands, whereas the continent of Africa 

 within the tropics including only the small islands in the proximity of the coast, 

 is designated by " Central Africa." 



The present work was originally published in German under the title " Die 

 Blütenpflanzen Africas " (Beriin, R. Friedländer & Sohn, 1908). A new 

 edition being desirable, I have preferred the English language, and I am 

 indebted to Dr. A. B. RENDLE, of the British Museum, for revising my 

 translation. 



The plates were drawn by the Vienna artist JOSEPH FLEISCHMANN 

 from herbarium specimens kindly lent from the collections of the Hofmuseum 

 at Vienna and the Jardin botanique de I'Etat at Brussels by their respective 

 keepers Dr. A. ZAHLBRUCKNER and Dr. E. DE WILDEMAN. Drawings 

 already published have been used for a few plates only ; these are duly 

 indicated. 



FRANZ THONNER. 

 VIENNA (AUSTRIA), September 1913. 



