56 



tirassveld may consist of a fairly intimate mixture of several 

 of them. A. appendiculatus is usually a mountain species 

 -and A. intermedins var. punctatus and A. pertusus, which 

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

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

 Veld. 



The majority of the species belonging to the sub-genus 

 Cynibopogon are taller and coarser and represent a type which 

 is either transitional to Forest or Scrub, or which forms a 

 stage in the hydrosere. The commonest are the Dobo or 

 Tambookie grasses A. nardus var. validus (isiQunga), a lemon- 

 scented grass, .4. auctus and A. dregeanus (uQunga). A. 

 dichroos is an early flowering tall growing species often 

 Tuderal. A. cymbarius is similar but flowers late. Its variety 

 lepidus ( = A. tamba Torre and Harms) belongs to the hydro- 

 sere, being found around the margins of Vleis. 



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

 (x about £0). 



The genus Andropogon, being a sub-tropical type, 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 clumps. 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 A. hirtus (see Fig. 4). Ridges 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 



