404 J. W. BEWS. 



and mountain genera as Festnca, Poa, Microchloa, 

 Harpechloa, Antlioxanthum, Agrostis, Avenastrum, 

 Brachypodium, Koeleriaj Pentaschistis and Dan- 

 tlionia is worthy of note. The coast belt grasses all belong 

 to tropical tribes, but the most tropical of them are not 

 grassveld species. Although there are a large number of 

 coast belt grasses, comparatively few are found in the grass- 

 veld itself. Many are vlei species, many are ruderal, and a 

 still greater number of very distinctive species of grass are 

 found in the moist marsin of scrub and forest. Among- them 

 all the temperate tribes, such as the Ave note, Festuce^ 

 and Hordefe, are very poorly represented. The few species 

 Avith temperate affinities which do occur, e. g. Ehrharta 

 calycina, E. erecta, are sea-shore species, or (e. g. 

 Bromus unioloides) are ruderal and have been introduced. 

 (e) Aspect Socies in the GtEASSVeld.— In addition to the 

 grasses thei^e occur in the grassveld a large number of other 

 species, which, in former papers, were dealt with under the 

 general heading of '' associated veld plants." In the Natal 

 grassveld there are two chief aspects, the vernal and 

 autumnal. The vernal aspect phuits are, to a certain extent,, 

 " complementary " to the grasses, since they are, as a rule, 

 deeper-rooted, having underground stoi'age organs of one 

 kind or another (bulbs, corms, rhizomes, tubers, tuberous 

 roots). Nevertheless, they are not altogether complementaiy, 

 for they gradually diminish in numbers and tend to disappear 

 if the grass is left unburnt, or, in other words, the grasses 

 can suppress most of them under natural conditions. 'I'he 

 laying bare of the soil in spring by the burning of the grass 

 enables the sun's rays to heat the soil to a sufficient depth to 

 cause the vernal plants to commence gfowth before the 

 grasses, which have no underground water storage and have 

 to wait for the spring rains. The various vernal as]iect 

 socies spread rapidly on burnt areas. On the other hand, in 

 unburnt areas they cease to be prominent, though they may 

 remain dormant under the soil for several years, as is shown 

 by the fact that where grass has been left unburnt for a 



