764 
Journal of Agr icultural Research 
Vol. XXVIII, No. 8 
Salinity 
A single test of the upper 15 inches of soil taken in the group of palms north of 
Indio showed only a small amount of salt, 0.16 per cent. The surface of the soil 
where this group occurs is crusted with white salt, mostly sulphates (Table I, 
sample 4). 
SUMMARY OF PHYSICAL CONDITIONS, AND ADAPTATIONS 
The palm trees indicate a good supply of water available all the year. The 
soil, although saline, is not excessively so, due probably to the constant supply of 
comparatively fresh water from the subsoil. 
Since water is available throughout the summer and since high temperatures 
are necessary for the palm’s growth, most of its growth is made during the summer. 
P 1 JKLEWEED ASSOCIATION 
TOPOGRAPHICAL RELATIONS 
The pickleweed areas, like the salt grass areas, are not as common or extensive 
in the Southwestern desert region as in the Great Basin. Pickleweed covers the 
central and lower portions of Coachella Valley (fig. 2). The area covered is a 
more or less continuous strip, very broad at the edge of the Salton Sea, where 
it is coming in as an early stage of a succession on the saline soil as the water 
recedes, and narrowing toward the upper part of the valley into a narrow strip 
along the bottom of a dry creek. In the Gila Valley and throughout the rest of 
the Southwestern desert region there is but little pickleweed, and where it does 
occur it is mixed with other plants in small areas usually along the rivers. 
BOTANICAL COMPOSITION 
While most of this area in Coachella Valley is pure pickleweed ( AUenrolfea 
occidentalis (S. Wats.) Kuntze) it is often associated with scattered plants of 
saltgrass (Distichlis spicata (L.) Greene), arrowweed ( Pluchea sericea (Nutt.) 
Coville), Atriplex lentiformis (Torr.) S. Wats., Atriplex canescens (Pursh) Nutt, 
and Dondia torreyana (S. Wats.) Standi. No annuals are found here because of 
the high salt content of the surface of the soil. 
APPEARANCE 
The areas in Coachella Valley consist of large flat tracts bearing scattered 
plants of pickleweed. The spaces between the plants are white with a heavy 
coating of salts (PI. 8, B). A typical area shows dark bushy brownish-green 
plants from 1 to 2 feet high. Large tracts of this kind are monotonous in appear¬ 
ance. In the early spring the plants are brown, the parts above ground dying in 
winter. 
PHYSICAL CONDITIONS INDICATED 
Soil Moisture 
The soil is more permeable than that of the desert-sage land. The texture in 
the third and fourth feet is considerably lighter than that of the desert-sage land 
(Table XIX). The soil moisture (Tables XIX and XX) is greatly increased by 
the high water table. In spring the water comes almost to the surface and the 
land is very boggy, more so than any other type of land in the valley. While the 
saltgrass land is very wet, the sod formed tends to make it firmer on the 
surface. In the fall the surface foot of soil is no longer boggy, but there is a good 
supply of available moisture in all 4 feet of soil. 
