The common larkspur (Delphinium nuttallianum) is a member of the buttercup family. Also called a bilobed larkspur or delphinium, this beautiful purple flower can be found throughout the West in mountain meadows, open forests and sagebrush plains – everywhere except the driest sites.
The five sepals of this perennial are larger and more conspicuous than the four actual petals. Larkspurs exhibit bilateral symmetry (irregular in shape but with both halves the same). The upper sepal is extended into a long, nectar-bearing spur. The two lower petals are bilobed while the upper two petals of D. nuttallianum are white with purple veins. The few leaves have 3 to five divisions and sharp tips.
Larkspur is highly toxic to humans and livestock (other than sheep) causing abdominal pain, nausea, depressed respiration and eventually asphyxiation if ingested. The toxic principle is delphinin, an alkaloid. If feed is plentiful, livestock on pasture or the range will not eat larkspur, preferentially chosing other vegetation. Thus larkspur is only dangerous to grazing animals under near-starvation conditions.
Sheep are immune to larkspur poisoning and are sometimes used to graze larkspur off infested areas.
Being poisonous there are no culinary or common medicinal uses for larkspur. The Karok Indians did use larkspur as a source of blue dye for their bows and for decorating pottery.
These larkspur are in our meadow pasture (Lookout CA). Our horses graze this pasture for several weeks each summer with no ill effects. With ample grass available the horses will not eat the larkspur.