Tailcup lupine, sometimes called silver lupine, is a perennial herb 

 of the pea family (Leguminosae). The specific name is a Latin word 

 meaning tailed (from cauda, tail), and alludes to the short prolonga- 

 tion backward of the upper part of the calyx, or outer floral cup; 

 hence the common name, tailcup lupine. This plant ranges from 

 Washington and Oregon (east of the Cascades) to California 

 (chiefly, if not entirely, east of the Sierra Nevada Mountains), 

 Nevada, Colorado, and Idaho. It may possibly also inhabit Arizona, 

 New Mexico, and Montana, although it is not now definitely known 

 as occurring in those States. It grows chiefly between elevations of 

 about 3,000 and 8,500 feet, characteristically appearing in rather 

 dry, well-drained soils from the sagebrush type up to open coniferous 

 timber stands. It is one of the common lupines in the ponderosa pine 

 belt, growing chiefly in parks and openings where, especially in 

 California, it is often associated with Idaho fescue (Festuca idahoen- 

 sis} and bitterbrush (Pwshia tridentata). Tailcup lupine is fairly 

 common over much of its range and often is locally abundant. 



This species is one of the more palatable kinds of lupine cattle and 

 horses, on the average, utilize about 30 percent of the herbage, and 

 sheep and goats about 50 to 60 percent. This relatively high use is 

 unfortunate, because the plant is particularly poisonous to cattle and 

 horses, as well as somewhat toxic to sheep. 1 In this respect it is 

 almost unique among the lupines, only one other species (and that a 

 very closely related one), looseflower lupine (L. laonflo'rm), being 

 identified definitely as seriously poisonous to cattle and horses. Tail- 

 cup lupine may also be poisonous to game animals, although deer 

 graze it rather freely, and no authentic reports of deer losses attrib- 

 utable to it have been received. 



Claw r son * reports that cattle poisoned by tailcup lupine show 

 symptoms similar to those caused by larkspur, especially the general 

 weakness and muscular trembling, followed by convulsions and 

 prostration. Horses poisoned by this plant act as if they have colic ; 

 sheep appear very nervous and excitable. The species may be 

 dangerous even when associated with an abundance of harmless, 

 palatable plants easily available to livestock; losses, however, are 

 more likely to occur and be more severe if other palatable vegetation 

 is scarce. Comprehensive experimentation is needed for a complete 

 determination of the poisonous properties of this plant. 



Although the lupines as a group are well known, many species are 

 so similar in appearance that it is extremely difficult to distinguish 

 between them unless one has a wide knowledge of the genus and con- 

 siderable botanical training. However, the following characters 

 taken together will usually identify tailcup lupine : The stems, about 

 8 inches to 2 feet high, are densely appressed-silky- or satiny-hairy ; 

 at least some of the lower leaves are long-stalked; the abruptly 

 sharp-pointed leaflets (characteristically about 7 to 9) vary in num- 

 ber from 5 to 11 or more, and are densely silky-hairy on both sur- 

 faces; the outer flower part (calyx) is somewhat spurred or humped 

 on one side and densely hairy; the upper petal (banner) is hairy on 

 the back. 



1 Clawson, A. B. TWO LUPINES SHOWN TO BE POISONOUS TO LIVESTOCK. U. S. Dept. 

 Agr. Off. Rec. 10(9) : 71. 1931. 



