Tall Larkspur: Some Reasons for Its Continuing Preeminence as a Poisonous Plant

Abstract

Tall larkspur (Delphinium barbeyi Huth) causes more financial loss than all other poisonous plants growing on the Wasatch Plateau of Central Utah. It is found in the subalpine zone above 9,500 ft and is only locally abundant on a small portion of this area. Dense stands of tall larkspur occur mainly on sites where deep snowdrifts accumulate during the winter. Plants in the communities on these snowdrift areas remain tender, succulent, and green while the palatability of plants on the surrounding areas declines with increased maturity. This differential palatability limits the effectiveness of livestock management to reduce losses. Control of tall larkspur must be selective. Adequate vegetative cover must remain to protect sites which are predisposed to erosion. The survival capacity of tall larkspur indicates the need for surveillance schedule and provisions for retreating plants not killed by previous treatments.