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 P. aineriiana has real value ; the long wand-iike 

 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 chai'acterislic of the Pniniis genus. As it first 

 appears it is liquid and colorless, but with exposure to the 

 air it hardens and becomes dark. AVhen 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 



Piitinis pfiimylvdiiii-a. 



A rapid-growing short-lived Ucc 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 

 tlie north a shriib only. Roots librous. Common throughout the 

 northern states ; prefers a rich moist soil ; reaches its greatest size 

 on the moimtains 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 



