Scientific Name: Prunus virginiana
Distribution: Throughout the United States and Canada, but rare in the Southeastern U.S.
Type of Poison: Hydrocyanic acid or prussic acid
Signs of Poisoning:
Growth Characteristics: A shrub or small tree, growing erect, 6 to 25 feet tall, with horizontal branches, growing in dense thickets. Flowers April to July, fruits mature July to September. It reproduces from seeds, rhizomes, and basal sprouts.
Flowers/Inflorescence: Flowers are white and in long, dense clusters. The fragrant flowers have five sepals, five petals, and many stamens.
Fruits/Seeds: Produces a dark red to black, fleshy, cherry-like fruit. The fruit is tart and astringent, being ¼ to ½ inch in diameter.
Leaves: Alternate and deciduous, oval to somewhat oblong, with serrated margins. Leaves are 1 to 3½ inches long. Underside of leaf is somewhat paler than top of leaf. There are two glands at the top of the petiole. Leaves turn bright yellow to orange in fall.
Stems: Twigs slender, reddish-brown to orangish-brown. The bark is gray to black, with prominent "corky" spots on the bark (lenticels), which are reddish-white. The trunk is dark red. The wood is hard, heavy, and light colored.
Chokecherry grows where moisture is plentiful. It is found in thickets on hillsides and canyon slopes. It appears as a shrub or small tree among willows, poplars, and alders that grow along mountain streams.
Chokecherry begins growth early in the spring. Its growth is slow at high elevations.
Both sheep and cattle may be poisoned by chokecherry. Although most losses occur when feed is scarce, a few animals seem to prefer this plant to other forage. Cattle are sometimes poisoned by eating leaves on branches trimmed from cultivated chokecherry trees. The toxic substance — hydrocyanic acid — is found principally in the leaves. Leaves become less toxic as the growing season advances. Although the hydrocyanic acid content of chokecherry leaves varies, ingestion of about 0.25% of an animal's weight in leaves can be fatal. Wilted leaves as well as fresh leaves are poisonous.
For chokecherry to be fatal, an animal must eat a toxic dose in a relatively short period — 30 minutes to an hour. Hydrocyanic acid inhibits cellular respiration in all the body organs and causes respiratory failure. Signs of poisoning come on rapidly, and death may follow within a few minutes.
Keep hungry or thirsty animals off areas where chokecherry is abundant.
The action of hydrocyanic acid is so rapid that it is usually too late to treat an affected animal after the signs are recognized.
Some poisoned animals may be saved by immediate treatment. For both cattle and sheep, use 20 cc thiosulfate mixed with 10 cc of a 10% solution of sodium nitrate given intraperitoneally or intravenously. Do not let animals become overexcited while they are being treated.
L.F. James, R.F. Keeler, A.E. Johnson, M.C. Williams, E.H. Cronin, and J.D. Olsen. Plants Poisonous to Livestock in the Western States. U.S. Department of Agriculture, Agriculture Information Bulletin 415, 90 pp. 1980.
Pratt, Mindy S. Chokecherry. Range Plants of Utah. 2008. Utah State University Extension Service. 3 July 2009. http://extension.usu.edu/rangeplants/htm/chokecherry