( 277 ) 



13. — A revision of the genus Pteronia (Compositae). By J. Hutchin- 

 son, Assistant, Kew Herbarium, and E. P. Phillips, Assistant, 

 8. Afric. Mus. 



Fifty years have now elapsed since the publication of the third 

 volume of the ' Flora Capensis,' which was devoted mainly to Harvey's 

 account of the South African Compositae. The material upon which 

 the work was based was mainly the collections of the earlier travellers, 

 such as Thunberg, Masson, Niven, Ecklou, Zeyher, Drege, and a few 

 others. The huge collection made by Burchell was, however, not at 

 that time available for general study, but a few of his specimens, 

 mostly in the De Candolle herbarium, are quoted. It was only in the 

 families elaborated in the later volumes of the work (vol. 4 onwards) 

 that his plants were fully worked out. Since the appearance of the 

 third volume our knowledge of the Cape Compositae, as of the rest of 

 the flora, has greatly increased, not so much perhaps in the discovery 

 of large numbers of novelties, as in the case of Tropical Africa,* but 

 rather in the distribution and habitat of the described species. For 

 these acquisitions to our knowledge we are indebted to those ardent 

 collectors of South African plants among whom may be mentioned 

 especially MacOwan, Bolus, Wood, Gralpin, Schlechter, with many 

 others, and more recently the collectors on the Percy Sladen Memorial 

 Expeditions under the direction of Prof. H. H. W. Pearson. 



According to the late Dr. Bolus.f the Compositae of South Africa 

 constitute on an average something like 17 per cent, of the entire 

 phanerogamic flora, and in one region, his Upper Region, as much as 

 28 - 4 per cent. The importance to South African botany of bringing 

 our knowledge of thi& family as much up to date as possible will, 

 therefore, be obvious. 



Failing a complete revision of the first three volumes, in itself a huge 

 task, it appears advisable where necessary to revise periodically the 

 larger and more cumbersome genera, giving keys for the determination 

 of the species, with full descriptions and a detailed account of their 

 distribution. With this object in view a commencement has been 



* Stapf in Kew Bull. 1906, pp. 239, 240. 



t Bolus, 'Sketch of the Floral Regions of South Africa ' (1905). 



21 



