172 
Journal of Agricultural Research 
Vol. i, No. 2 
puberulous without and minutely hairy on the inner surface. Ten or twelve stamens 
on short filaments are arranged in two series. The petals, 2 mm. long, are white, 
broadly obovate cuneate, with erose margins and without claw. 
In the pistillate form the calyx tube is rather more campanulate. There are minute 
abortive stamens and the pubescent ovary is surmounted by a smooth style, 2 to 3 
mm. long. The mature fruit, borne on a very short peduncle, is coarsely pubescent, 
irregularly globose, 1 to 1.3 cm. long, having a distinct ventral ridge with a shallow 
furrow through the center and two or three pairs of small concentric ridges arising 
from the base and disappearing toward the rounded apiculate apex. 
The thin, dry pericarp does not split as in Prunus andersonii and P, eriogyna. 
The thin-walled stone is smooth surfaced excepting minute sharp ridges correspond¬ 
ing to those of the outer surfaces. Kernel scarcely edible because of the strong prussic- 
acid flavor. 
Mr. F. V. Coville seems to have been the first to notice that the 
flowers of this species were otherwise than perfect. His description 
contains the following paragraph: 
The flowers are polygamo-dioecious, a fact which explains Dr. Gray's diffi¬ 
culty 1 in identifying Torrey's plants with others subsequently collected. In the pre¬ 
vailingly male flowers the petals in our specimens are elliptical lanceolate, appressed 
strigose on the back, 3 to 3.5 mm. long; the filaments 2 mm. and the anthers 1 to 1.2 
mm. in length, while the style is 1 to 2 mm. long, and the pistil sterile. In the fertile 
flowers the petals are ovate, glabrous on the back, 2 to 3 mm. long, the filaments 
0.6 to 0.8 mm., the anthers 0.4 mm., and devoid of pollen, and the style about 2 mm. 
long. The sterile flower is the one figured by Torrey (loc. cit., pi. v). The form 
and length of the petals probably vary considerably. 2 
Schneider 3 recognizes this and the two following species as “subdi- 
dcisch * ’ (subdioecious). 
THE TEXAS ALMOND 
The Texas almond, first collected by Lindheimer south of New Brauns- 
fels, Comal County, Tex., “not far from Cebolo Cr./’ occurs in the north¬ 
west suburbs of San Antonio and occupies an imperfectly known region 
southwestward to the Rio Grande and beyond 4 apparently restricted to 
the limestone soil of the Cretaceous formation. (Fig. 2.) 
The region of the lower Pecos near the Rio Grande is one of deep 
deposits of soft cretaceous limestone rock, deeply eroded and very broken. 
The soil over the hills is often very thin or the bare rock is wholly exposed. 
In the broader washes some soil is beginning to collect in the form of 
miniature bottom lands, occasionally overflowed by the run-off from 
heavy rains. Along these washes there is sometimes a fringe of scrubby 
growth of hackberry, oak, the western black walnut (Juglans rupesiris ), 
the “chapote,” or Mexican persimmon (Diospyros texana ), and similar 
arid land forms. It is in these situations that the Texas almond is found 
1 Proc. Amer. Acad, x., p. 70 (1874). 
2 Coville, F. V. Botany of the Death Valley expedition. Contrib. Nat. Herbarium, v. 4, p. 91, 1893. 
3 Schneider, C. K. Illustriertes Handbuch der Laubholzkunde, Bd. 1, Lfg. 5, Jena, 1906, p. 598. 
4 “ . . . Gravelly places and ravines between Devil's River and the Rio Grande; also in Chihuahua; 
Parry. Bigelow." Torrey, John. Botany of the boundary. Emory, W. H. Report of the United 
States and Mexican Boundary Survey ... v. 2, Washington, 1859, p. 63. 
