ROSE FAMILY 
nigra or Canada Plum. The fruit is smaller, rounder than 
that of the Canada Plum and bright red in color. Many cul- 
tivated varieties have been derived from this species, as it 
quickly responds to the gardener’s care ; it also forms an ex- 
cellent stock upon which to graft the domestic plum, 
Professor Sargent says of this tree, “As an ornamental 
plant 2. americana has real value; the tong wand-like 
branches form a wide, graceful head which is handsome in 
winter and in spring is covered with masses of pure white 
flowers followed by ample bright foliage and abundant showy 
fruit.” 
Exudations of gum from the bark of plum and cherry trees 
area very common sight. This is generally known as Cherry 
gum and is a characteristic of the Pravus genus. As it first 
appears it is liquid and colorless, but with exposure to the 
air it hardens and becomes dark. When dry it is brittle, with 
an insipid, sweet or astringent flavor. 
The wild plums have been found to be the hosts of the 
Hop-aphis which is so destructive to the hops just at the time 
of their maturity and as a consequence it has been recom- 
mended that all plum trees in the vicinity of hop fields should 
be cut down. 
WILD RED CHERRY. BIRD CHERRY 
Primus pennsylvdnica. 
A rapid-growing short-lived tree with bitter aromatic bark and 
leaves, thirty to forty feet in height, regular slender branches which 
form a narrow head more or less rounded at the summit; often in 
the northa shrub only. Roots fibrous. Common throughout the 
northern states ; prefers a rich moist soil; reaches its greatest size 
on the mountains of Tennessee and often occupies large areas after 
they have been cleared by fire of their original forests. Will grow 
in exposed locations. 
Bark.—Dark, red brown, conspicuously marked with lenticels, 
smooth and polished on young stems and branches, but on older 
trunks separates horizontally into broad papery plates. Branchlets 
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