Introduction. 



The grasses belong to the family of the Poaceae or 

 Gramineae, a well-defined natural group of plants. They are 

 found all over the world, and altogether over 3,000 species 

 are known. In South Africa there are about 500 species, a 

 few of which have been introduced since the advent of the 

 white settler. From the economic standpoint no family of 

 plants is of greater importance since the (iramineae include 

 the cultivated cereals, and the natural grasses are the chief 

 food of stock in a pastoral country such as South Africa. The 

 study of the individual species is not simple even for the 

 expert, since they are separated by somewhat artificial char- 

 acters, and the tribes into which they are divided are not well 

 defined. On the other hand the collections of South African 

 grasses that have been made are remarkably complete as com- 

 pared with some other families. The earliest collections were 

 made by Ecklon, Zeyher and Drege, and these were worked 

 up and descriptions were published by Nees in 18-11. Since 

 that time mam* new species have been discovered, and the 

 whole group has been thoroughly revised, and careful descrip- 

 tions of the individual species have been given by Dr. Stapf 

 in the Flora Capensis. Medley Wood in "Natal Plants" has 

 given illustrations of 200 species, but he added little to Dr. 

 Stapf s descriptions. Stapf has also written an interesting 

 phytogeographical sketch of the distribution of the various 

 genera and tribes in the separate regions of South Africa. 1 



Though these works have been available for many years, 

 there are very few in South Africa who are familiar with the 

 grasses. Students of Botany, I find, experience great diffi- 

 culties in making use of the kev to the genera given in the 

 Flora Capensis, not that the work differs in that respect from 

 other similar manuals. Many of the statements in all such 

 keys are found on close inspection to be vague and contra- 

 dictory. When T began a study of the plant succession in the 

 grasslands of South Africa, I became convinced of the neces- 

 sity of devising a simpler means of recognising 1 the different 

 grasses, and consequently the artificial key wliich is given 

 here was drawn up. The nomenclature adopted throughout is 

 that of the Flora Capensis, since a work of this kind is hardly 

 the place where any revision of nomenclature should be under- 

 taken. 



1. Stapf, O. " Die Gliederung der G-raserflora von Sudafrica." 

 Festchrift Aseherson, Berlin, 1904. 



