Journal of Agricultural Research 
Vol. I, No. 2 
158 
botanical description. A few wild grape hybrids are recorded in the 
writings of Dr. Engelmann. 
Among plums a few definite natural hybrids of the wild species have 
been recognized, and the later judgment of Prof. Bailey on Prunus 
hortulana , described by him as a species, is that it is a group of varieties 
which are hybrids between Prunus americana and the southwestern 
species, Prunus angustifolia} 
On the whole, surprisingly few authentic hybrids have come into 
existence without the aid of man among uncultivated plants. 
Examples of natural or unassisted hybridization among cultivated 
plants are somewhat more common, as though as a result of cultivation 
some of the safeguards which nature had established against the inter¬ 
breeding of species had been broken down, but here again the sum total 
of such crosses is small. 
These considerations make it the more interesting and significant when 
we find such a divergent form of plum as this so-called wild peach hybrid¬ 
izing so freely with the local forms with which it comes in contact. 
How numerous these hybrids may actually be is only a matter of con¬ 
jecture, and only a close survey of the entire region of occurrence of 
Prunus texana can disclose this. The detection of these at any stage of 
active growth is rendered comparatively easy by the strongly marked 
characters of this species. The narrow, pubescent, strongly glandular- 
serrate leaves, as well as the pubescent calyx cup with glandular-serrate 
lobes, added to the notable character of the pubescent fruit with its 
peculiar pile-covered stone, all help to render one of this class of hybrids 
conspicuous and unmistakable. Three of the more striking forms in 
three widely separated localities had been noticed and taken into culti¬ 
vation years ago by observant ranchmen interested in fruit growing. 
Systematic search by the writer and other observers, though for only a 
few days and over a very limited area, disclosed the other eight recorded. 
It is significant that in five out of seven of the most important regions 
where the wild peach is associated with the wild species of plums these 
spontaneous crosses have been found. In these same sections hybrid 
forms between the numerous species of true plums are rare or have not been 
detected. More conclusive evidence can hardly be offered that Prunus 
texana crosses with a number of species of the true plums with unusual 
readiness, far more readily than these species cross among themselves. 
It is on account of this fact and the promise which it holds out to enter¬ 
prising plum breeders that it has been thought worth while to describe 
in rather minute detail a number of these natural hybrids, including 
several which as horticultural varieties have little or no value. 
The first of these varieties was learned of during an exploring trip 
around Kingsland, Llano County, in March, 1910, and through the kind- 
1 Willard, S. D., and Bailey, L. H. Notes upon plums for western New York. New York Cornell Agr. 
Exp. Sta., Bui. 131, p. 170, 1897. 
