Western Larkspur (Delphinium hesperium)

Synonyms: Tall Larkspur / Tall Mountain Larkspur / Duncecap Larkspur
An upright perennial, 3-6 feet tall, upper stems are sticky/glandular; small flowers are pale blue to purple, spurred, and numerous in tall, dense clusters; leaves are palmately divided; flowers June to August. Found across the western U.S. Best in partial sun, moist soils, considered an invasive weed in some areas; poisonous to livestock.