We have seen and photographed the flowering plant at left in just one location, a steep, north-facing hillside of a terrace in lower Hot Springs Canyon. At our elevation close to 3,300 feet, the most likely species is Delphinium scaposum, "Tall Mountain Larkspur" or "Barestem Larkspur". The formal criteria given by Epple and by Niehaus et al. (also cited on main Wildflowers page, pp. 358-9) seem to point with some ambiguity in this direction. (However, Epple says there are 10 species of Delphinium in Arizona.[Ibid.])
Click on the image at left to enlarge it.
These flowers have five sepals (petal-like divisions of the outer parts of the flower), and 4 petals, and are "Royal blue with whitish center; backward-projecting spur" (Epple, op.cit.): see below and click on each image to enlarge it. Notice also the single spur, visible at right on the left-hand image. The 5 sepals stand out clearly in the right-hand image. Compare Epple's photos, Plate 759.
The leaves are described similarly by Epple and Niehaus, Epple describing the Barestem as "Dark green, basal, palmately divided into lobes with rounded tips;" (ibid.), and these fit that description -- as well as the drawing in Niehaus, more or less, though there are also some pointed tips present, and viewed close-up the rounded lobes have slightly pointed tips. Click on each image to enlarge it.
Here is a final set of flowers illustrating the main features quite clearly:
Epple's final comments are as follows: "Perennial herb with leafless stem. Contains delphinine and other toxins poisonous to humans and livestock. Hopi Indians use ground flowers in religious ceremonies." (ibid.)