56 



Grassveld may consist of a fairly intimate mixture of several 

 of them. A. appendiculatus is usually a mountain species 

 and A. intermedium Tar. punctatus and A. pertusus, whicli 

 agree in Laving the lower glume pitted, occur usually in the 

 early stages of sub-seres, hut may be found in more stable 

 Veld. 



The majority of the species belonging to the sub-genus 

 Cymhopogon are taller and coarser and represent a tyj^e -which 

 is either transitional to Forest or Scrub, or -u-hich forms a 

 stage in the hydrosere. The commonest are the Dobo or 

 Tambookie grasses -.1. nardus var. validua (isiQunga), a lemon- 

 scented grass, .4. ductus and i.4. dregeanus (uQunga). A. 

 dichvoos is an early flowering tall growing species often 

 ruderal. ..4. cyinharius is similar but flowers late. Its variety 

 lepidus { = A. tainha Torre and Harms) belongs to the In'dro- 

 sere, being found aroujid the margins of Yleis. 



Fig. 4. — Transverse Section of a portion of a leaf of Andropogon hirtiis 

 (x about eO). 



The genus Andropogon, being a sub-tropical tyi^e, does 

 not show the extreme xerophytism of the South Western and 

 Western semi-desert species. The species have mostly spread- 

 ing root systems, and tufted habit, growing in strong bunches 

 or chimps. The innovation shoots are either extravaginal or 

 intravaginal or both. The leaves are flat or folded condupli- 

 cate. They agree fairly closely with the species here illus- 

 trated .4. hirtua (see Fig. 4). Eidges are not prominent, but 

 there is a very distinct midrib, with large water storage cells. 

 The vascular bundles are more than half surrounded by 

 chlorenchyma, and are not strongly girdered, but they have 

 sclerenchyma both above and below. The thin-walled cells 

 between the patches of sclerenchyma on the upper surface 



