54 



Three species, viz., A. microphylla, A. hirsute, and .4. 

 setifolia have a more eastern distribution, being- characteristic 

 of the Karroo mountains, and the Stormberg and Drakens- 

 berg. A setifolia sometimes forms small societies on the flat 

 dry plains of the Eastern Karroo, and transitional belt 

 between that and Eastern (irassveld, and is a good grazing 

 grass. All the species of Achneria are very xerophytic with 

 narrow, short, folded, or setaceous leaves, and deep roots. The 

 spikelets are more or less shining or glistening. The cross 

 section of a leaf of A. capensis is shown in Fig. 3. Note the 

 abundant sclerenchyma, which forms large girders, the pro- 



Fig. 3. — Transverse Section of a leaf of Achneria capensis (x about 120). 



minent ridges and motor cells, the thick cuticle and the large 

 lower epidermal cells. There is no definite midrib. The 

 unshaded portions between the girders is all green chlorophyll 

 tissue, usually found packed full of food. There are no 

 smaller vascular strands between the main ridges. 



Agropyrum distichum. A ruderal species. Leaves with 

 unequal ridges and motor cells. Blades sub-pungent. 



Agrostis. Chiefly a temperate genus. The most impor- 

 tant species ecologically is A. lachnantha, which occurs all 



