02 



Chloris. The most widely distributed species is Ch. 

 petraea, which extends from the Cape to Natal and the Trans- 

 vaal. It is a common pioneer in the open veld of stony hill- 

 sides. Ch. pycnothria- is a very common ruderal in Natal,, 

 being found usually along roadsides and footpaths. The 

 other two, Ch. gayana (Rhodes' grass) and Ch. virgata, are 

 also common ruderals, but they occur in the Veld, and are 

 widely distributed. They are very nutritious grass and make 

 a good hay. They are tropical in their affinities and occur 

 also in Tropical Africa. They only rarely assume dominance 

 anywhere in climax Grassveld, being easily ousted by other 

 grasses. Ch. petraea is perennial and flowers early, the others 

 are annual or sub-perennial and flower late. If the Veld grass 

 is burned before they have time to seed they are easily 



Fig. 7. — Transverse Section of a portion of a leaf of Chloris gayana 

 (x about 70). 



destroyed, which fact illustrates the way in which early burn- 

 ing leads to deterioration in the quality of Veld Grassland. 

 Other aspects of the same subject will be discussed at length 

 later. Fig. 7 shows the cross section of a leaf of Ch. gayana. 

 The chlorophyll tissue is confined to a ring round the vascular 

 bundles. The whole upper half of the leaf consists of water 

 storage tissue, which is free from chlorophyll. There is a 

 distinct midrib, and the leaf folds conduplicate as it dries. 

 There is very little sclerenchyma below each bundle, but tlie 

 margins of the leaf (see right hand side of the figure) are 

 more strongly fibrous and slightly thickened. 



Crossotropis grandiglumis is a very distinctive species 

 witli spikelets distant from each other along the numerous, 



