ATLAS OF AMERICAN AGRICULTURE. 
Figure 33.—California needle grass on land protected from grazing. (Bunch-grass.) This open stand 
of perennial bunch grasses probably represents the original grassland of the central valleys of California, 
ft is very similar to the bunch-grass vegetation of Oregon and Washington, which is also giving way as a 
result of overgrazing to introduced annual grasses. For this reason the California grassland has been in¬ 
cluded with the grasslands of Oregon and Washington in the bunch-grass division. Perris', Calif. 
Figure 34.—A luxuriant growth of annual brome grasses (chiefly Bromus rubens). (Bunch-grass.) 
Wild oats and filarees are often important. Growth usually takes place in the winter or early spring, and the 
plants soon ripen seeds and remain as a dry dead cover throughout the remainder of the year. Porterville, 
Calif. Photographed by A. W. Sampson. 
pied by weedy vegetation consisting largely of annual 
brome grasses ( Bromus rubens, B. hordeaceus, B. tec- 
torum) , filaree {Erodium cicutarium) , wild oats 
{Arena fatua and A. ba/rbata) , fox tail ( Hordevm mu- 
rinum) , bur clover ( Medicago hispida) , and many 
other weedy plants (fig. 34). The wheat-grass bunch 
type of Oregon and Washington is being reduced to 
this weedy condition where the original grasses are 
entirely killed out by overgrazing. Such seems to 
have been the history of the California grassland, 
and perennial grasses persist in sheltered or pro¬ 
tected areas. These are chiefly California poa ( Poa 
scabrella) and California needle grass ( Sfipa pulchra ) 
(fig. 33), which seem to represent the original plant 
cover. The stages in the reduction of this bunch- 
grass type to the present weed-grass type is not yet 
known to science. E. O. Wooton has recently ob¬ 
served the following stages, which the sheepmen of the 
region confirm: The original (1) bunch-grasses, lu¬ 
pines, clovers, and borages gradually give way as a 
result of overgrazing, to (2) wild oats and bur clo¬ 
ver, and these in turn to (3) filaree, (4) fox tail, and 
finally to (5) red brome (fig. 34). At present this 
grassland is characterized largely by weedy annuals. 
Following the winter rains these short-lived grasses 
produce a luxuriant carpet, dotted by many showy 
flowering plants such as California poppy {Esch- 
scholzia ccdifomia) . The vegetation matures early 
and remains during a long summer rest period in a 
dried condition. The winter rains cause the seeds 
to germinate, producing the later Winter and early 
spring growth. 
Land in this area, when irrigated, is used for alfalfa, 
rice, and sugar beets, and is good for fruit, including 
grapes, apricots, and peaches, as well as citrus, figs, and 
other semitropical fruits. The dry farm lands produce 
barley and wheat, much of which is cut green for hay. 
SHORT GRASS (PLAINS GRASSLAND). 
Short grass characterizes the Great Plains lying 
east of the Rocky Mountains and for the most part 
west of the one hundredth meridian (fig. 2). The 
grasses are low-growing (figs. 35-39) and shallow 
rooted, owing to a low precipitation, 12 inches in north 
central Montana to 22 inches in western Texas, which 
falls largely just preceding and during the growing sea¬ 
son. In most cases it does not penetrate more than 2 
feet before it is exhausted by the grass cover. A layer 
of carbonate accumulation in the soil at a depth of 
from 8 to 20 inches marks the depth of the periodically 
moist surface soil layer. There is no storage of avail¬ 
able soil moisture from year to year and the subsoil 
is permanently dry. The growth of deep-rooted 
plants, therefore, is not possible. The frost-free 
period varies from about 100 to 200 days, but the 
growth season of the short grasses seldom exceeds 
90 days. Grama grass, which is more characteristic 
of the north, requires about 100 days to complete 
its growth and produce seed, while buffalo grass, 
which is limited to the south, has a much shorter 
growing season of about 40 days. Moisture is the lim¬ 
iting factor, and the buffalo grass in Colorado may 
bloom either in June or August, depending upon the 
distribution of the moisture supply. During dry years 
this great expanse presents the appearance of an end¬ 
less carpet, while in wet years taller plants develop on 
the short-grass sod and give to it a more mixed ap¬ 
pearance. 
Dry farming has been undertaken in nearly all parts 
of the short-grass region, but it has proven profitable 
only in the less arid portions. Under irrigation the 
soil generally is productive and has been most success¬ 
fully employed in growing cereals, alfalfa, sugar beets, 
potatoes, and other vegetables. This region is not 
thickly settled. Although most of the land has been 
taken up, less than one-eighth was in harvested crops 
in 1919. Probably nearly a twentieth was crop failure 
or tying idle or fallow. 
In the east-central portion corn is an important crop 
and is usually grown in rotation with winter wheat. 
Spring wheat is grown in North and South Dakota, 
Montana, northwestern Nebraska, and eastern Wyo¬ 
ming. Of the cereals, wheat, barley, and oats are most 
successfully grown in the northern portions, while 
sorghums and corn are the principal crops in the south. 
In the extreme northern portion flax and potatoes are 
important. The northern portion is given over more 
particularly to grain production and the southern por¬ 
tion to coarse forage. The most valuable agricultural 
D 
Figure 35.—Western wheat grass on sod composed of buffalo 
grass and grama grass. (Short grass.) During favorable years it 
is important as hayland, as shown by the shocks in this picture, 
but during dry years little or no hay is produced. It is limited 
largely to the clay, or gumbo, lands of South Dakota and adjacent 
States. Phillip, S. Dak. 
land in this section lies in the northern and eastern 
portions, since drought is more severe in the south and 
west. 
The short-grass vegetation may be subdivided into 
several associations, including the following; 
Grama grass. 
Grama-mountain sage. 
Grama-Muhlenbergia. 
Galleta grass. 
Grama-buffalo grass. 
Wire grass. 
Western wheat grass. 
Grama-western needle grass. 
Grama grass (fig. 36).—The grama-grass area on 
the west is separated from the mixed grama and west¬ 
ern needle grass and grama-buffalo grass areas on the 
east by a line running near the North Dakota-Montana 
boundary, cutting west of the Black Hills, and ex¬ 
tending down close to the mountains in Colorado. 
This area also includes the higher valleys in Colo¬ 
rado, New Mexico, Arizona, and isolated spots in 
Utah (fig. 3). The vegetation is dominated largely 
by grama grass ( B outeloua gracilis, formerly called 
B. oligostachya) , which often constitutes an almost 
pure sod. Prominent spring flowers are the white 
mountain lily ( Leucocrinum montanum ), pasque 
flower {Pulsatilla hirsutissima) , phlox ( Phlox hoodii), 
wild onion {Alliu/m textile ), and ground daisy {Town- 
sendia exscapa). Over the northern portion of the 
area mountain sage {Artemisia frigida) is prominently 
associated with the grass. In Montana and Wyoming 
grama grass often alternates with the sagebrush type, 
and is modified by the abundant admixture of nigger 
wool {Garex jilifolia ) and June grass {Koeleria cris- 
tata ). In the south, in Colorado, Texas, and New 
Mexico, where the soil is rocky or where the short 
grasses have been damaged by overgrazing, it is often 
modified by an admixture of match weed {Gutierrezia 
sarothrae and several allied species). The grama-grass 
type marks the portion of the short-grass area which 
has the lowest evaporation and the coolest, shortest 
season, but which has a relatively low rainfall. This 
is an important grazing section, and in the northern 
portion grain farming has developed in many localities. 
Grama grass and mountain sage. —Along the mountain front 
grama grass (B outeloua gracilis) is often mixed with a great 
variety of plants which are more typical of the mountain grass¬ 
lands. Among these may be mentioned mountain sage (Ar¬ 
temisia frigida), nigger wool ( Garex filifolia), yarrow ( Achil¬ 
lea millefolium), Eriogonums of various species, Pentstemons, 
wild roses, and lupines. These characterize an area in which 
the rainfall is greater than that of the adjacent grama-grass 
land. The soils are often not well developed but consist of 
loose granitic gravels. Where land is level and favorable for 
cultivation conditions are much better than in the grama- 
grass area farther east. The small grains, spring wheat, oats, 
barley, and rye, are the chief crops grown in this area. 
Grama grass and Muhlenbergia. —In the southern portion of 
the grama grass area, especially in Colorado and New Mexico 
near the mountains, conditions become so extreme as to tem¬ 
perature and drought, that grama grass gives way in part to 
Muhlenbergia gracilUma. With this often occurs the cane cactus 
(Opuntia arborescens) . This associes characterizes land of in¬ 
ferior production, even as grazing land, and of doubtful value 
for crop production. 
Galleta grass. —The grassland dominated by galleta 
grass {Hilaria jamesii) covers extensive areas in 
northern New Mexico and Arizona, and pushes far 
into the Utah desert. The grass forms an open sod 
cover, often practically pure, and when dormant it 
usually presents a uniform light-colored appearance. 
At a distance it can be detected from the winter-fat 
areas of the northern desert only by the slightly yel¬ 
low tint of the dried foliage. During a series of dry 
years it often replaces sagebrush and is in turn re¬ 
placed by sage during periods of more favorable mois¬ 
ture supply. This community represents the greatest 
extension of the short-grass land into the Great Basin 
area. It covers land not unlike that described as sage 
or rabbit brush land, and can not be distinguished on 
the basis of moisture relation and alkali content from 
sage land. It is probably the best grazing land in the 
southern portion of the northern desert shrub, with the 
possible exception of areas covered by winter fat. 
Grama-buffalo grass (fig. 37).—This type extends 
over western Nebraska, Kansas and Oklahoma, eastern 
Colorado and New Mexico, and the Panhandle of 
Texas (fig. 3), and is dominated by almost equal quan¬ 
tities of grama grass {Boutelouxi gracilis') and buffalo 
grass {Bulbilis dactyloides). It occurs as a uniform 
open sod, and is the most typical short grass of the 
