486 MISS L. S. GIBBS ON THE 
and the other being outlined by the above evergreen species, 
causing that uninterrupted green line along the banks so 
conspicuous during the dry season, in comparison with the 
leafless veld. Tke Eugenia is accompanied by a fringe of 
Phragmites, in which Saliv sp., zEschynomene cristata, Sesamum 
Baumii, Alternanthera sessilis, Commelina nudiflora, Vigna 
luteola var. villosa, Asystasia coromandeliana, and Nephrodium 
unitum occurred. Clumps of Papyrus and the splendid grass 
Erianthus teretifolius break the Phragmites ring in places. 
Succeeding the Eugenia, the commonest species comprised young 
trees of the evergreen Garcinia Livingstoni with their long 
candelabra-like branches, Avgelia pinnata, Trichilia emetica, 
Croton barotsensis, and Ficus sp. with Crotalaria flavi- 
carinata, Byrsocarpus coccineus var. parviflorus, and Phyll- 
anthus reticulatus as undershrubs; the trees being covered with 
a dense growth of lianes, of which the commonest were Tiliacora 
Junifera, Paullinia pinnata, Hippocratea obtusifolia, Jasminum 
mauritianum, Abrus precatorius, and the semi-scandent Capparis 
tomentosa. Erlangea Schinzii was a common annual, and 
Phenix reclinata and a Hyphene sp. were abundant, attaining 
a great height on some of the larger islands. 
On the smaller islands there was little or no tree-growth, and 
beyond the usual fringe of Phragmites, a mass of vegetation 
consisting of Walafrida chongweensis, Hebenstreitia Holubii, 
Pollichia campestris, Pavonia hirsuta,and Momordica Balsamina 
formed a dense growth over the sandy soil. 
On the exmerged rocks, which are covered when the river is in 
flood, the perennial form of Denekia capensis with Floscopa 
glomerata and Hemigraphis prunelloides flourished ; also Rham- 
phicarpa tubulosa, where more soil had accumulated. Of water- 
plants the Podostemacee were represented by three species— 
the dead remains of a Spherothylav sp. on all exposed surfaces, 
while in shallow areas Tristichia alternifolia, in flower and fruit, 
covered rocks and stones, and Tristichia trifaria from the 
extreme edge of cataract were growing under water. Vallisneria 
spiralis grew densely where the rocks shelved into deeper waters, 
the female flowers forming conspicuous floating green masses, 
where the plant could be no longer seen. Potamogeton natans 
and Hydrilla verticillata were very common and the only pond- 
weeds seen, and floating masses of Jussieua sp. occurred near the 
banks. 
