154 Vegetation of the Colorado Desert. [ZOE 
California. At various localities, especially near the foothills of 
the mountains, there are high, rocky ridges that stand well out 
on the desert proper, unconnected with the higher main range. 
A large area of the flat portion is below the level of the sea and 
at one time was an inland lake into which the waters of the Colo- 
rado River emptied. 
Shells of species said to be now living in that river are scattered 
thickly over the ground in many places below the old beach line, 
that is even now well marked. Below this old beach line there is 
a scanty flora and it nearly all seems to have been brought in by 
the waters of the Colorado. The flora growing on the surround- 
ing higher lands stops at the beach line, excepting where a gulch 
or dry.stream bed has allowed the rains to carry seeds on to the 
lower levels. The channels through which the Colorado at high 
water runs into the Salton Basin are lined with species of shrubby 
Atriplex and Baccharis, and over the level portion grow many 
chenopods, especially Monolepis. ‘There are numerous small an- 
nual Eriogonums, some Spheralcea Coulter? and other Arizona 
plants. Around the lakes, shallow depressions filled with Colo- 
rado River water, is a band of vegetation, the outermost mainly 
Prosopis, and that near the muddy edges consisting mostly of 
Nama stenocarpum and Aster spinosus. T,ater in the season, after 
an abundant overflow from the channels, great quantities of A/r7- 
plex Palmeri appear and grow to a height of ten feet in some 
places and Sesbania macrocarpa is plentiful. ‘The Cactaceze, so 
abundant in the surrounding regions, do not appear below the 
beach line, and I have not seen a single one on the old lake bed. 
Some plants, such as Larrea, are as common on the slightly ele- 
vated parts and sand drifts as they are above the beach line, but 
they grow also along the Colorado River. The name Colorado 
Desert does not seem appropriate to much of this region now, for 
the water of the Colorado is irrigating a large extent of it, and in 
a short time there will be many accessions to its flora from seeds 
brought in by the-gardener and agriculturist. 
Some additions to the Flora of California from the vicinity of 
this region are worthy of note. Ammobroma Sonore was col- 
lected by Alfred Stockton near the Colorado River, Malperia 
