This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Native. Perennial. Propagates by seeds.
Time of bloom: April to July, varying with altitude.
Seed-time: June to September.
Range: Northern Colorado to California, and northward to British
Columbia. Habitat: Hillsides and mountain valleys, ascending to about eight thousand feet.
As this plant seldom exceeds a foot in height, stockmen and herders are accustomed to speak of it, and also of Delphinium bi-color, as the "Little Larkspurs," in contradistinction to their neighbor, Delphinium glaucum, which sometimes attains seven feet and is called the "Big Larkspur" or "Large Larkspur." It is generally regarded as less poisonous than D. bicolor, although E. V. Wilcox1 reports a case on a Montana range where a flock of six hundred sheep were poisoned by it, of which two hundred and fifty died; and the same poisonous alkaloid, called delphocurarin, has been extracted from both these species. (Fig. 113.)
1 "Thirty Poisonous Plants of the United States." Farmers' Bulletin No. 86, U. S. Department of Agriculture.
The plant springs from a cluster of thickish, oblong tubers, fringed with fine feeding rootlets. Stem simple, slender, often bent or flexuous, both it and the foliage finely hairy; the lower leaves have long petioles, slightly dilated at base, and are deeply five-parted, the segments again twice or thrice divided; the upper leaves are small, oftenest of three nearly linear segments. Raceme terminal, slender, the flowers few, on long, nearly erect pedicels; they are large and showy, deep violet-blue, the sepals and the spurs nearly equal in length, bearded outside; the two upper petals are yellowish but are distinguishable from D. bicolor because they are not net-veined. Follicles three, widely recurving at maturity, the seeds black and winged on the outer angles.
Means of control the same as for Delphinium bicolor.