Spurred Lupine (Lupinus caudatus). Photo Courtesy of Dave Powell, USDA Forest Service, http://www.bugwood.org/
Lupinus sp. L.
Scientific Name Synonyms:
Life Span: Perennial or Annual
Growth Characteristics: A complex group of erect to ascending forbs, 10 to 24 inches tall, with 1 to several stems growing from a shortly branching taproot. Flowers June to August, fruits mature July to September. It reproduces from seeds.
Flowers/Inflorescence: Flowers are small and spurred at the base, color can range from white to purple. They are attached to the stem by a slender stalk (raceme). Each flower has 5 large stamens and 5 small stamens.
Fruits/Seeds:Legume (pea pod), somewhat flattened, usually hairy, bearing 2-12 seeds per pod.
Leaves: Palm shaped with finger-like segments. They can be hairy to silky and silvery on both surfaces.
Widespread from valley bottoms to high mountain areas. Because this plant is a legume it has nodules on its roots that form a symbiotic relationship with bacteria that fix nitrogen and thus aids in building soil fertility.
Soils: Adapted to a broad range of soil textures, but most abundant in coarse-textured and well-drained soils.
Associated Species: Aster, mountain brome, aspen, and sagebrush.
Uses and Management:
Lupine is poor forage for cattle and fair for sheep before the legume fruit develops. It provides fair to good forage for elk and deer. Cattle may be attracted to the legumes and graze them selectively. Lupine is poisonous, especially to sheep and horses. Alkaloids are concentrated in the seeds and occasionally in the young plants. Plants are poisonous either green or dry, and poisoning seldom occurs when other forage is adequate. Poisoning can cause blindness within 10 minutes. The most characteristic symptoms of lupine poisoning are: 1) excitement, leading to running about and butting into other objects; 2) convulsions, accompanying attacks of dyspnea; and 3) heavy and labored breathing. In sheep, symptoms may not appear for 1 - 24 hours after eating the plant. Poisoning can also cause fetus deformities in pregnant animals. Some lupines can cause "crooked calf" disease if consumed between the 40th and 70th day of gestation.
A drug has been extracted from lupine for management of cardiac arrhythmias.