Unusual conditions that force livestock to eat toxic quantities of poisonous plants may cause large losses. This happens when biting insects force cattle to spend a long time in brush where larkspur is prevalent. Cattle may eat large amounts of larkspur just to maintain their daily intake requirements. The flowers are deep blue of purple and have the characteristic spurs of the delphinium flower group. Tall larkspur is found in the foothills of the Rocky mountains, growing in moist draws or coulees and on hillsides at higher elevations.
Larkspur needs some shade and a well-drained, fertile soil.
The common habitat of larkspur is aspen forests. Large amounts of larkspur may be found in recently cleared land that has been left unbroken. Therefore, as livestock move from one pasture to another, the risk of livestock poisoning will vary. Until recently tall larkspur had been considered more poisonous when it is young than at any other stage of growth. However, new research indicates that the principle poisoning agent, methyllycaconitine, is found throughout the tissue of young larkspur, and concentrates in the reproductive parts of the plant as the plant matures.