40 
Transactions .of tJie Royal Society of South Africa. 
Savannah. 
This formation belozigs to the same type as that described by Bews (I. c.^ 
p. 309) under the names of " Thorn Veld " or Thorn Savannah," a remark- 
able park-like form of vegetation which covers very extensive areas in South 
Africa. The ground is covered with a variety of perennial grasses with 
which are mingled a profusion of herbaceous perennial phanerogams, while 
scattered at relatively wide intervals are found some trees (chiefly Acacia 
horrida, Willd.) and a few hairy shrubs and undershrubs, e. g. the ubiquitous. 
Hibiscus ]jeduncidatus ; Lasiosyplion anthyUoides, var. macrophylla, Meisn. 
(Thymelaeaceae), which has a silvery grey appearance through the covering 
of both leaf-surfaces, and even the tube of the yellow corolla being covered 
with long appressed silky hairs ; and a species of Wius (Anacardiaceae),. 
with a dense felt of long brownish hairs over its stems, leaves and in- 
florescences. 
The principal G-ramineae included in this formation are JDigitaria 
sanguinalis, Scop., var. ciliaris, Prain, a low tufted grass without a rhizome, 
the leaf sheaths and nodes of which bear long, spreading, silky hairs ; 
EriantJius Sorghum, Nees., a perennial grass with a creeping rhizome and 
tufts of leaves and inflorescences a metre high ; Cyinjjopogon marginatus, 
var. validus, very similar in habit to the foregoing. The two latter grasses 
are the two alternative dominants of this formation. Other associates of 
the same oecological type are Panicum aequinerve, Nees, a grass with many 
short, slightly ciliate, cauline leaves ; and two Cyperaceae, Scleria melanom- 
phala, Kunth., and Cy})erus comjMctus, Lam. 
Scattered among the Grrasses and Cyperaceae great numbers of other 
phanerogamic plants flourish. Some of these may be mentioned : 
Disa '})olygo7ioides, Lindl., a terrestrial orchid with glabrous sheathing 
leaves and a dense spike of small flowers. 
Gladinlus op'positifloTus, Herb., with tall, sword-like, hard, ribbed, 
glabrous leaves and a long spike of large pink flowers. 
Gladiolus atroruhens, N. E. Brown, a previously undescribed species 
(see Kew Bulletin, 1914, p. 135). 
Eidophia pur]jurescens, Rolfe, a rare terrestrial orchid. 
Pachycarpus dealbatiis,'E.'NLe-y. (Asclepiadaceae), with large, stiff, scabrid 
leaves, and the stems and petioles shortly hairy : near the forest 
border only. 
Asclepias gihha, Schl., with slender stem and linear leaves and a few 
bristly hairs. 
Tragia durbanensis, 0. K., a trailing perennial covered with stinging 
hairs. (Euphorbiaceae.) 
■ Pimpinella sp. (Umbelliferae), very like P. saxifraga in appearance, and 
covere d with very short pubescence. 
