This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Delphinium trollifolium, Gray
Native. Perennial. Propagates by seeds.
Time of bloom: April to June.
Seed-time: June to August.
Range: Oregon, Washington, Idaho and British Columbia.
Habitat: Moist soil along streams, foothills; meadows and pastures.
A very beautiful plant but in some localities it bears the unpleasant names of Cow-poison or Cow-killer. Stem two to five feet tall, slender, leafy. Leaves large, three- to seven-parted, often somewhat kidney-shaped at base, the segments wedge-shaped and deeply cut and lobed at the tips. Racemes large and loose, often more than a foot long in the larger plants; flowers large and deep blue with the two upper petals white; spur and sepals about equal in length, often three-fourths of an inch. Follicles smooth, the seeds with a thin margin or wing at the end. (Fig. 114.)
Fig. 113. - Small or Menzies Larkspur (Delphinium Menziesii). X 1/4.
Means of control the same as for the Purple Larkspur.
Fig. 114. - Western Larkspur (Delphinium trollifolium). X 1/5.
Fig. 115. - Common Barberry (Berberis vulgaris). X 1/4
 
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