SURROUNDING LAKE TORRENS. 107 
Then again among these are seen the rarest forms, Hemisteirus psilo- 
trichodes, Pimelea simplex, Picrophyta calcarata, Pholidia santalina, and 
"Eriosciadium argocarpum, a quickly perishable Umbelliferous plant, 
which conceals its small flowers beneath the thick wool of its fruits. 
With these associates also a fugitive from India, Trichodesma Zeilani- 
cum. In the clefts of the barest rocks is found seeking shelter and 
nourishment the beautiful but poisonous Z/sofoma petrea, for the most 
part in isolated spots, as well as Biatora decipiens, a Lichen of all zones, 
and Pomaz rupestris, attaching themselves to the walls of rock. 
The valleys, which are periodically converted by thunderstorms into 
torrents, conduct downwards little rills too quickly drying up, which 
run through the stony diluvial land, and are recognized at a distance 
by the band of lofty red-wooded Eucalypti (E. rostrata). But rapidly 
as the water is carried off, there still remains in isolated holes enough 
for the black native, who lies in wait here for the thirsty emu, and 
enough also of the element of life beneath the rubble of the river-bed, 
to give nourishment to a numerous and extremely varied host of 
plants, as Malva brachystachya, Abutilea cryptantha, the magnificent 
Hibiscus notabilis, various species of Sida, Dodonea lobulata (a transi- 
tion-form between the pinnate and simple-leaved species), the creeping 
Desmodium Novo-Hollandicum, the odoriferous Schizocorona floribunda 
(Cynanchum floribundum, R. Br.), in spite of its emetic qualities eaten 
raw as food by the savage natives, the prickly Solanum lithophy- 
tum, petrophilum, and eremophilum, Rostellularia pogonanthera, and 
noble Grasses (Andropogon chrysatherus, inundatus, Panicum glaree, 
Chloris Moorei, Amphipogon calycinus, etc.). All these plants, which for 
the most part indicate an approach to the tropic, penetrate in varied 
association the gravelly stratum, to root themselves in the moist de- 
posit beneath, and along with them are ranged many related southern 
species, such as Loudonia citrina, Picrophyta albiflora (a bitter Goode- 
nia-like herb), Rutidosis auricoma, the large-lowered Senecio megaglossus 
and magnificus, with other ornamental Composite, Prostanthera striati- 
flora, perhaps the finest of its splendid genus, Acacias as everywhere 
abundant and of new and multiform species, Hyrea rubelliflora, the 
Conyza of Australia, which bears the name of the courageous discoverer 
of this region. Sparingly diffused, but far excelling all the other 
flowers in its incomparable beauty, Clianthus Dampieri, the queen of — 2 
Australian flowers, spreads its long shoots over the gravelly soil; and 
