174 
Journal of Agricultural Research 
Vol. I, No. 2 
Twigs of young growth often puberulous, reddish brown or silvery gray; older wood 
with silvery gray or iron-gray bark. 
The leaves, which are conduplicate in the bud, borne singly on young growth but 
fascicled on short spurs on older wood, are spatulate or narrowly elliptical; apex 
rounded, refuse or mucronate; base cuneate, entire or with one to several minute 
teeth on either margin, and rarely one or two near the base, glandular tipped, firm 
and leathery, pale bluish green, glabrous or faintly puberulous at the base, i to 3 cm. 
long, 0.5 to 1 cm. wide; petiole short, slender; stipules 2 mm. long, acuminate, ciliate 
margined. 
The minute flowers, borne singly or paired, on short peduncles, are usually crowded 
on short, budlike fruiting spurs. They appear with the leaves in February or March 
and are minute and dioecious by the abortion of the stamens in the fruiting form and 
of the pistils in the opposite form. In both types the inner surface of the calyx is finely 
hairy. In the pistillate type the calyx tube is obconic, glabrous; lobes triangular, 
acute; peduncle 3 mm. long, puberulous; ovary and lower portion of the style finely 
pubescent. There are usually 15 or more abortive stamens. Petals white, about 
2 mm. long, obovate cuneate, with sinuous or erose margins and short, stout claws. 
In the staminate flowers the tube is slightly broader, the stamens 10 to 15 or rarely 
16 to 20 on short filaments, usually with a stamen opposite each petal, one or two 
against each calyx tooth, and an irregular number disposed on the upper surface of the 
tube. The pistil is abortive and much reduced. 
Fruit globose, apiculate and with shallow ventral furrow, pubescent, 1 to 1.5 cm. 
long, the thin, dry sarcocarp scarcely dehiscent; the stone smooth with but a slight 
furrow on ventral surface. 
THE MEXICAN ALMOND 
The Mexican almond was the first of this group to be described, 
but to-day is the least known of all of them. Found in the high moun¬ 
tain regions of Mexico, it has been little collected and it is not known that 
it has as yet been brought into cultivation. 
Judged by the pubescent thin-fleshed fruit with its smooth, oval stone 
its relationship would be considered near to the Texas almond (Prunus 
minutifiora) which crosses the border into Chihuahua, but its more 
slender and less spinose twigs and especially the serrate, finely pubescent 
leaves indicate that it is a quite distinct species. In 1823 Humboldt and 
Bonpland found it growing in arid hills between Pachuca and Moran 
(Estado de Hidalgo) at an altitude of 7,800 feet and describe it as a 
shrub 3 feet high with sparse, reflexed, divergent, glabrous branches and 
subangular pubescent twigs. 
Parry and Palmer collected this shrub in the region of San Luis Potosi 
‘ at an altitude of 6,000 to 8,000 feet, which would agree well with the 
altitude at which the original specimens were collected by Humboldt and 
Bonpland. 
The majority of specimens in American herbariums have been col¬ 
lected by Mr. C. A. Purpus, of the University of California, to whom 
the writer is indebted for the most recent information on the occurrence 
and habits of this species. 
The following description of this species is made from material in the 
United States National Herbarium, specimens contained in the herbarium 
