146 



abundant. There is often, however, an admixture of xero- 

 jjhytic species of Aristida, Eragrostis, etc., which are much 

 poorer. 



A simple cross section of the leaf of a grass enables one 

 to gaunfe the amount of hard sclerenchyma present, and con- 

 sequently whether the grass is likely to be palatable to stock, 

 but this is not a safe guide to the nutritive value of the grass, 

 for many xerophytic species are nutritious in spite of their 

 sclerenchyma. Xerophytic species, however, are slow growing 

 as compared with. the mdre mesophytic types, and this of 

 course is a most important factor in connection with their 

 value for pasturage. 



In the cereal grasses, which have long been under the 

 closest observation, it has been found that differences in the. 

 chemical nature of the grain are often correlated with simple 

 morphological variations in the flower or in the plant itself, 

 e.g., the presence of hairs of a particular kind on the glumes 

 of barley has been found to indicate that the variety is good 

 for brewing purposes. It would be a very diffic\ilt matter to 

 explain the reason for such correlations, but where they have 

 been shown to exist they are extremely useful for the purposes 

 of selection. I hesitate somewhat about laying stress on 

 certain correlations which I have observed in South African 

 grasses, which are known to be good grasses, but one such 

 seems to be remarkable enough. The group of grasses which 

 have their spikelets arranged on one side of the rachis, i.e., 

 secund (see Nos. 7-25 inclusive in the key to the genera) are 

 nearly all good or very good grazing grasses. The tribe 

 Chlorideae is best represented among them by the genera 

 Cynodon, Microchloa, CteniuTn, Harpechloa, Chloris, Eleusine, 

 and Dactyloctenium. The tribe Paniceae has Pas f alum, Digi- 

 taria, Stenotaphrum, and one section of the large genus 

 Panicinn. Tetrachne dregei (Festuceae) is also a good Moun- 

 tain Veld species. If this correlation should be fully estab- 

 lished, it will be extremely useful for it will enable anyone, 

 at a glance, to recognize one very large class of useful grasses. 

 It may be further noted that a large number of them belong 

 to Mountain Veld. 



The cultivation of grasses. The cultivation of the various 

 cereals is a subject by itself, with which I do not propose to 

 deal. Other grasses are cultivated for pasturage and fodder, 

 or ensilage. Most of those commonly cultivated in other parts 

 of the world, the seeds of which are listed by seedsmen, are 



