Tall mountain larkspur, barestem larksur
Arizona, Nevada and Utah, plus small areas of adjoining states
Between 10 and 24 inches
Woodland, grassland, scrubland, hillsides; up to 5,000 feet
Round overall, up to 2.5 inches across, divided into 3 to 9 lobes, irregularly toothed
The lobed green leaves and the grey-green stems of delphinium scaposum are smooth and nearly or completely hairless; leaves may have a very fine hair covering, and are often somewhat shiny. Leaves are concentrated around the base, borne on long stalks (up to 4.5 inches). The inflorescence is an elongated cluster of between 10 and 24 or more heads, each about one inch across, and occupying up to 12 inches at the top of the stem.
Individual flowers are borne on short, ascending stalks, and are alternately arranged. They have five spreading, dark blue sepals, the uppermost extending backwards into a curving spur, and four smaller sepals, of which one (the upper) is white, curved, and notched at the tip, while the remainder are purple. The colored petals have hairy surfaces. Below the petals is a group of whitish stamens, topped by yellow-brown anthers. Flowers at the base of the cluster open first.