218 LEGUMINOSAE (PULSE FAMILY) 
marks are often bordered by thickets of Black Cherry sprouts. 
The leaves of this and kindred plants, under certain conditions, 
contain a dangerous quantity of hydrocyanic acid, commonly called 
prussic acid, a most virulent poison. When eaten by cattle and 
sheep, the complex chemical changes that take place within the 
animals’ stomachs liberate the poison, frequently with fatal effect. 
The common Choke Cherry (Primus virginiana) also con- 
tains prussic acid, but in a less amount than the Black Cherry. 
Leaves from large trees or old but stunted shrubs are not nearly so 
dangerous as leaves from young, rapidly growing sprouts. Both 
fresh and wilted leaves are poisonous, but chemists have demon- 
strated by experiment that “Leaves wilted in bright sunlight to 
about 75 per cent of their original weight, or until they begin to 
appear slightly limp and to lose their gloss, yield the maximum 
amount of prussic acid.” It is stated that a half-pound of Black 
Cherry leaves is a fatal quantity for a cow to eat, and a much less 
quantity will kill a sheep. 
Means of control 
Yearling Cherry sprouts may be easily and quickly pulled when 
the ground is soft, leaving no stubs to put forth more leaves. Older, 
shrubby growths should be closely cut, or, better, grubbed out, 
before coming into leaf, if they are situated where cattle or sheep 
are likely to browse them. Often grazing animals will eat litter 
that is lying on the ground, even though they have not contracted 
the habit of browsing from standing growth; therefore all the 
brush cut should be put out of harm’s way by piling and burning. 
WILD SENNA 
Cassia marilandica, L. 
Other English names: American Senna, Yellow Locust Plant. 
Native. Perennial. Propagates by seeds. 
Time of bloom: July to August. 
Seed-time: September to October. 
Range: New England to Florida, westward to Michigan and 
Indiana. 
Habitat: Moist, open ground; pastures and meadows. 
The roots of Wild Senna are spreading, contorted, woody, and 
black, mostly horizontal, but yet gathering nourishment from the 
