Plant Distribution in South Africa. 291 
Peninsula, and are not included in the 320). On the other hand, the 
eastern (Natal) trees and shrubs which occur in the Cape Peninsula are 
confined to the small forest areas on the slopes of Table Mountain, where 
the rainfall is greater, and the summer heat is tempered by the south- 
eastern mist clouds. 
A few species which are common to Natal and the Cape are chiefly 
sea-shore plants, and extend right round the coast, e. g. Cryptostemma 
niveunt , Dimorphotheca fruticosa , Osteospermum moniliferum , Passerina 
filiformis , Mesembrianthemum edule, Che note a diffusa, Cynanchum obtusi- 
folium , Chironia baccifera , Olea capensis , E hr hart a erecta , E. calycina , 
Sporobolus pungens , Stenotaphruni glabrum , though several of them do 
extend slightly inland. 
A careful examination of the whole 195 shows that, with the ex- 
ception of one or two forest trees ( Podocarpus latifolia , Ocotea bidlata , 
Curtisea faginea ), these also belong to early stages in the succession (the 
initial stages of the xerosere). Take the grasses for instance. No fewer 
than 43 species are common to the Cape and Natal. Of these, 18 are 
either ruderal or vlei (marsh) grasses, 4 are sea-shore species, and the 
remainder are all primitive colonizing types, even including the xerophy- 
tic varieties of Anthistiria iniberbis , which are found in the Cape Peninsula. 
The species Sporobolus indicus , Eragrostis curvula , Aristida angustata , 
A. barbicollis , Andropogon hirtus , Cynodon dactylon are examples. Refer- 
ence to my published work on ‘ The Grasses and Grasslands of South 
Africa’ (8) will make clear how closely similar the grasslands of the 
whole western side of South Africa are to the initial stages of the suc- 
cession in the eastern grassveld region. The chief pioneer genera which 
help to establish grassland in all the eastern areas are Aristida , Era- 
grostis , Sporobolus , and Cynodon . These same genera are dominant in the 
climax stages of the primitive semi-open grassveld of the drier areas 
towards the west, and extend through the Karroo and semi-desert forma- 
tions as well. 
The trees and shrubs which are common to the Cape Peninsula and 
Natal are also particularly interesting. Some of them, e. g. Ilex mitis , 
Myrica conifera , are pioneers in the hydrosere, but the majority are 
light-demanding, deep-rooted, xerophytic species which in Natal grow out- 
side the close forest, and act as pioneers in the xerosere, preparing the way 
for the more mesophytic, more ombrophilous kinds. I have described 
in detail elsewhere (6, 7 ) how Acacia horrida (A. karroo ) is the most 
important pioneer in the extensively developed thornveld. It invades 
grassland, and a great many species which cannot themselves act as 
pioneers, grow up underneath it and finally often overtop it and kill it. 
It is one of the most widely distributed species in South Africa. Another 
pioneer species, Myrsinc africana , which is very important in the establish- 
