67 



folded like that of D. disticha, but there is comparatively 

 little sclerenchyma, and the ridges are not prominent. The 

 ■stomata are shown on the supper side. On the lower side 

 there is very thick cuticle. The majority of the cells are seen 

 to be packed as full as they will hold with food material. The 

 vascular bundles are not girdered. 



Fig. 11.— Transverse Section of a portion of a leaf of Bigilaria ternata 

 (x about 60). 



Difjilai'ia. This genus is very closely allied to Panicum, 

 D. ternata is a common early flowering ruderal. D. sangain- 

 ■alis is equally common in autumn and D. horizontalis is also 

 abundant then. These are all annuals and are widely distri- 

 buted. D. debilis and D. tenuiflora are also annuals, but are 

 somewhat rare, only being found in Natal. D. monodactyla, 

 D. argyrograpta, I), eriantha, D. setifolia, D. diagonalis, D. 

 tricholaenoides, D. flaccida are all perennials and belong to 

 the primitive stages of Veld development. None of them 

 assume dominance except very locally, but they are common 

 ■enough, with the exception of D. argyrograpta and D. 

 flaccida, which, are chiefly Mountain Veld types. Some of the 

 perennial forms are rather xerophytic with filiform or seta- 

 ceous leaves, e.g., D. monodactyla and D. setifolia, but the 

 majority are mesophytic, and though they are common weeds 

 in cultivated land are considered very good grazing grasses. 

 There is less sclerenchyma in their leaves than in most other 

 South African grasses as is shown in Fig. 11, which is a cross 

 section of the leaf of T) .ternata. There is a very definite mid- 

 rib, but the ridges are almost obsolete. Broad bands of water 

 storage cells occur in the shallow furrows. The epidermis is 

 thin, and there are only very small patches of sclerenchyma 

 above and sometimes below the main bundles. The leaf 

 remains flat. Species of Panicum are similar, but show minor 

 differences in the arrangemnt of the sclerenchyma. 



Diplachne. D. fusca is a hygrophilous species found in 

 Vleis and along stream banks, and widely distributed over 



