Feb. 16, 1914 
Indicator Significance of Vegetation 
389 
toward the head of the valley. (PI. XLIII, fig. 2.) The boundaries 
between the areas occupied by the Kochia and by the sagebrush asso¬ 
ciations are usually very sharply defined. Equally abrupt is the change 
in salt content of the soil, as is well exemplified by the results of borings 
which were made on either side of the line of contact shown in Plate XLVI, 
figure 1. The location of the boring in the sagebrush association is 
marked by the position of the soil tube shown in the illustration. The 
two borings were only 20 feet apart. The results are given in Table VIII. 
TABLE VIII. —Salt content {in percentages of the dry weight of the soil) on either side of 
a line of contact between the sagebrush and Kochia associations . 
Depth (feet). 
Sagebrush. 
Kochia. 
1 
0.03 
O.31 
2 
•03 
I.49 
On the other hand, the boundaries between the Kochia and shadscale 
associations are usually indefinite. 
Kochia vestita , sometimes locally known as “white sage,” which is the 
dominant species of the Kochia association, is also a frequent component 
of the shadscale and greasewood-shadscale associations, reaching the 
shore of Great Salt Lake with the latter association. But the small size 
of the plants as compared with those of shadscale and of greasewood 
makes Kochia an inconspicuous member of these associations. 
In typical portions of this association Kochia vestita is almost the only 
species of flowering plant, except that where grazing animals are kept 
off the land, a small grass, Poa sandbergii , is very abundant. Eew other 
species occur, and these are seldom represented by numerous individuals. 
The following list includes all species of flowering plants which were noted 
as occurring in typical areas of the Kochia association: 
Botanical Composition 
Sphaerostigma pubens (Wats.) Rydb. 
Opuntia sp. 
Gutierrezia sarothrae (Pursh) B. and R, 
Appearance 
The Kochia association is the most uniform in appearance of the types 
of vegetation occurring in this valley (Pi. XLVI, fig. 2). It is virtually a 
1-species association. The height of the plants varies but slightly over 
large areas and usually does not exceed 6 inches. Owing to the low 
growth and the hairiness of the plants (see text fig. 7 and PI. XLVI, fig. 3), 
an area of Kochia presents at a little distance the homogeneous appear¬ 
ance of a gray blanket. Even at a distance of several miles, the strips 
Kochia vestita (Wats.) A. Nets. 
Poa sandbergii Vasey 
Erodium cicutarium L/Her. 
Lepidium sp. 
24395 — r 4-3 
