Common Name
Prince's plume
Botanic Name
Stanleya pinnata
Plant Family
Brassicaceae (Mustard family)
Prefers the dry, alkakine selenium-rich soils of western states. Prince's plume requires selenium for growth, and as such is an indicator plant for selenium-rich soils.
Animals Affected
Cattle, horses, sheep
Toxic Principle
Prince's plume will accumulate high levels of selenium. It is consequently seldom eaten by livestock. As an obligate selenium accumulator, its presence in the area is indicative of selenium-rich soils. Other plants in these soils will also contain selenium. Excess selenium in the diet causes abnormal hair and hoof formations as a result of selenium replacing sulfur in keratin, the primary protein in hair and hoof.
A perennial up to 5 feet in height. Stems are branched, the leaves are entire, pinnately compound, from 2-8 inches in length. The inflorescence is showy and plume-like. Individual flowers are yellow, each petal with a claw. The fruit is slender, nearly round in cross-section, with a stipe from 1-3 cm long.
Horses, in particular, may become severely lame. Initially circular ridges forms in all feet. As the hoof wall grows out, the ridges may crack and lames can be severe due to lamimitis and even sloughing of the hoof.
Affected animals should be removed from food or water sources containing more than 5 ppm. Diets containing adequate amounts of sulfur and copper have a protective effect against chronic selenium poisoning. Alfalfa has sulfur-containing amino acids and is a useful food source in areas where forages are high in selenium.
Integumentary System
Chronic selenium poisoning causes loss of the long hairs of the mane and tail.
Samples of hay or forages containing selenium levels greater than 5 ppm. should be considered potentially toxic. Blood levels of 1-4 ppm are typical of chronic selenium poisoning, whereas serum levels up to 25 ppm have been reported in acute poisoning. Liver and kidney levels greater than 4 ppm. are indicative of selenium toxicosis.
Special Notes
Prince's plume and other obligate selenium accumulator plants are often found in shale rock formations which contain high levels of selenium.
Circular hoofwall crack - selenium poisoning