Scientific Name: Cymopterus ibapensis
Distribution: Found in Oregon, Idaho, Nevada, and Utah, closely aligned with the Great Basin
Type of Poison: Two furocoumarins: xanthotoxin and bergapten
Signs of Poisoning:
Growth Characteristics: A perennial which grows 4 to 6 inches tall from a long taproot.
Flower: Small white or cream-colored flowers are borne in umbrella-like clusters about 1 inch across.
Leaves: Finely divided leaves that resemble parsley
Spring parsley, also known as Cymopterus or wild carrot, grows on well-drained soils, on rolling foothills and with sagebrush, pinyon pine, and junipers. It occurs at elevations of 4,000 to 8,000 feet. This is one of the first plants to begin growing in early spring. It flowers from late April to June and disappears by early summer. Plants are poisonous from early spring until they mature and dry in early summer.
Spring parsley causes a severe "sunburn" - or photosensitivity - in sheep and cattle. Poisoning differs from bighead, a type of photosensitivity caused by horsebrush but is similar to St. Johnswort poisoning.
Animals do not die from eating spring parsley, but losses occur when affected ewes or cows with blistered, sore udders refuse to nurse their young. Lamb losses often are high; calf losses usually are low.
Sheep are affected if they are exposed to direct sunshine after eating as much as one-quarter pound of the green plant. Sunburn varies from slight to severe; blisters form on areas of the sheep's body not covered by wool. In advanced poisoning, all the white areas of the body may be affected. Ewes are especially susceptible to spring parsley poisoning during March, April, and May.
Losses are primarily confined to lambs. On ranges where spring parsley is the first spring plant to emerge, an ewe may eat it soon after lambing. The udder and teats become so painful that the ewe will not allow the lamb to nurse. Newborn lambs die of starvation or dehydration. Surviving lambs usually are stunted from lack of milk.
Cattle are affected if they are exposed to direct sunlight after eating about 1 pound of the green plant. Hairless areas on the body become sunburned. Cows refuse to let calves nurse. In severe poisoning, all the white areas of the body may blister, and animals may lose weight rapidly.
Sheep and cattle recover gradually after they stop eating spring parsley.
To reduce losses from spring parsley, keep sheep and cattle off of infested ranges in early spring until other plants appear.
There is no known treatment for light-skinned animals that are affected by eating spring parsley, but they recover spontaneously if kept in the shade.
Research results show that spring parsley can be controlled with herbicides. Consult your local Cooperative Extension agent for more information. Follow all precautions for using herbicides.
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.