Journal of Agricultural Research 
Vol. I, No. 2 
166 
in habit of growth and branching, and color and texture of bark, but 
in size and color of flowers and character of fruit. 1 2 
One variety was noted with fruits of unusual size and having a fleshy 
development of the pericarp instead of the characteristic dry, leathery 
coating. 
A very strongly developed taproot is a characteristic of this species as 
well as of several others of the group. This has been very noticeable in 
growing seedlings. Seeds stratified in sand and exposed to open condi¬ 
tions of a severe winter of Washington, D. C., made a vigorous germination 
early in March, sending down strong taproots, while the tops were but 
two or three leaves above the ground. This must be recognized as an 
adaptation which has enabled them to survive under peculiar local con¬ 
ditions. Where wild-almond thickets occur there can usually be traced 
at a depth of i or 2 meters a layer of soil or sand where more permanent 
moisture is afforded than prevails near the surface. After the taproot 
has penetrated this layer small branches spread out into it and the 
moisture made available enables the plant to survive drought and heat 
which would have caused it to perish if supported by superficial roots. 
The range of occurrence of this species is shown on the map (fig. i) 
and is a region of such scant rainfall that little agriculture is possible 
without irrigation. Taking Carson City, Nev., as a typical station, 3 the 
mean annual precipitation is slightly above io inches, falling as low as 
5 inches in years of extreme drought. The 2 feet or more of snow forms 
a considerable portion of the annual moisture, the mean precipitation 
from April to September, inclusive, being but 2.4 inches. With summer 
heat occasionally reaching ioo° F., and the average winter temperatures 
of —20° F., some idea of the hardiness and drought resistance of this 
species can be formed. 
THE DESERT APRICOT 
This striking apricotlike species occurs only in certain out-of-the-way 
places in southern California. (Pis. XII, fig. 3, XIII, and XIV, fig. 1.) 
Confined chiefly to a narrow zone on the desert side of the San Ber¬ 
nardino and San Jacinto Mountains, the only frequented spots of its 
habitat are the village of Palm Springs at the foot of San Jacinto Peak 
on the south and the almost deserted hamlet of Banner at the foot of 
the mountains and just above the border of the desert below Julian in 
San Diego County. 
, In the Gray Herbarium the type specimen sheet has mounted upon it 
a specimen bearing the label i( Prunus subcordata , Bth.,” and in print, 
1 Mr. E. W. Hudson, of the Office of Crop Physiology and Breeding Investigations, while doing cooperative 
work at Wadsworth Agency, made numerous collections of this species in 1910 and noted that the flowers 
ranged in color from pale pink to a deep-rose color, and also varied greatly in size. 
2 Henry, A. J. Climatology of the United States. U. S. Dept. Agr. Weather Bureau, Bulletin Q, 
p. 920,1906. 
