THE PUBESCENT-FRUITED SPECIES OF PRUNUS OF 
THE SOUTHWESTERN STATES 
By Sii/AS C. Mason, 
Arboriculturist , Crop Physiology and Breeding Investigations, Bureau of Plant Industry 
INTRODUCTION 
The species of the genus Prunus described in this article occupy a 
unique position in the flora of the western United States from the fact 
that their relationship with the wild plums of the country is remote 
and they are more closely allied to some of the Asiatic species of this 
genus. 
Their economic importance arises chiefly from their close adaptation 
to the climatic and soil conditions of the Southwest, where fluctuations of 
heat and cold, severe drought, and considerable alkalinity of the soil 
must be endured by most tree crops. 
Adaptable stocks for the cultivated forms of Prunus capable of meeting 
such conditions are eagerly sought. Species with such characters which 
are capable of being hybridized with the old-established cultivated forms 
of the genus offer attractive possibilities to the plant breeder. This is 
especially true of the one edible-fruited form, Prunus iexana , which 
affords in aroma and flavor of fruit most attractive characters for combi¬ 
nation with other stone fruits of larger size and more staple commercial 
character. 
Instead of forming a homogeneous group, as has usually been be¬ 
lieved, these species fall into small groups of quite diverse character 
and affinities. To the plant breeder and student of their economic 
possibilities these relationships are of such importance that the following 
detailed study of them is deemed essential to an intelligent use of them 
in plant-breeding work. 
In parts of the country beyond the Rocky Mountains a few ranchmen, 
occasionally a solitary mining prospector, and a few local botanists 
know of curious bushy plants growing in desert wastes having plumlike 
bark and twigs, oddly shaped leaves, and small downy fruits with thin 
dry flesh which have won for them the local names “wild almond” 
in the Great Basin region, “wild peach” or “desert almond” for another 
form in the Mohave Desert, and “wild apricot” or “wild almond” for a 
third form in the foothills bordering the Salton Basin in southern 
California. 
A fourth form has been known for many years to the pioneers of 
eastern Texas, who have enjoyed eating the “wild peach” of their sandy 
Journal of Agricultural Research, 
Dept, of Agriculture, Washington, D. C. 
Vol. I, No. a 
Nov. io, 1913 
G -4 
