Synonyms: Delphinium occidentale, Delphinium occidentale ssp. occidentale, Delphinium scopulorum, Delphinium scopulorum var. glaucum, Delphinium scopulorum ssp. occidentale, Delphinium splendens
Western larkspur is a large perennial wildflower with one to several stems from 60-200 cm high. The stems are unbranched below the inflorescence and are hollow in cross-section. Plants may be glabrous to glaucous below and may become somewhat glandular-hairy within the inflorescence. The leaves are found both at the base of the plant as well as along the stems. The leaves become reduced in size gradually along the stem, although the basal leaves and the lowest leaves on the stems may be withered by flowering time. The blades range from 5-15 cm wide and are cut to the base, creating 3 main lobes. The lateral two lobes are further divided (but not so deeply) into 2-3 main segments. The blades are pubescent on both sides.
The inflorescence is a branched raceme, with the main raceme up to 35 cm long, narrow, and compactly flowered. The lateral racemes are shorter than the central raceme. The pedicels are spreading and typically shorter to longer than the spur. The calyx is finely haired to occasionally glandular-hairy. The color of the calyx ranged from deep bluish-purple (often streaked with white) to whitish. The calyx is puberulent or sometimes covered with gland-tipped hairs. The lateral sepals are ovate, oblong, or oblanceolate-elliptic in shape with rounded-acute tips and range from 9-15 mm long. The spur is 10-15 mm long, which is longer than the blade of the upper sepal. The lower petals are pale to deep blue. The upper petals are nearly white to pale blue. The fruits are usually hairy.
Western larkspur is found in along streams, in meadows, or on moist talus slopes in the mountains.
Western larkspur is found from the Blue Mts. of northeastern Oregon east to Montana and south through the Rocky Mts. to Colorado.
Close-up views of western larkspur as seen on moist slopes between Howard Creek and trail #1372 in the Wenatchee National Forest................July 25, 2009. Click most of the photos to see enlarged views (2-3X).