There are around a hundred species of lupine in North America. The most outstanding characteristic of lupines is their palmately compound leaves with elongated leaflets originating from a common point. The flowers are pealike, usually blue or violet but occasionally white, yellow or even red, and are borne on elongate racemes or clusters.
As members of the pea family, lupines are legumes and thus fix nitrogen, providing a nutritional contribution to the soil. On the negative side, most lupines contain poisonous alkaloids. Although all parts of the plant are toxic, the greatest amount of poison occurs in fully ripened seeds and pods. After ingestion breathing becomes difficult, the body begins to twitch and eventually convulsions, unconsciousness and even death can occur. Although not all species of lupine are poisonous, care must be taken, particularly with livestock, because the species are difficult to distinguish. Hungry livestock being trailed through ranges are often poisoned by lupine. The roots of certain lupine species were cooked and eaten by Native Americans, however, unless one has special knowledge about identification and preparation, lupines should not be eaten.
A common species in the West, silvery lupine (Lupinus argenteus), is found on the dry slopes of the Great Basin. A perennial that grows from seeds, silvery lupine has narrow, troughlike leaves. The banner petal (upper enlarged petal) is hairy on the back side.
These silvery lupine were growing near Lower Hat Creek (Shasta County CA).
Poisonous or not, the three common “blues” add beauty and color to the spring landscape.