Tall Mountain Larkspur - Delphinium occidentale

Tall Mountain Larkspur
Delphinium occidentale Wats.
Other names: duncecap larkspur

Family: Ranunculaceae, Buttercup
Genus: Delphinium

Description
General: robust, erect perennial from woody, thickened
rootstocks. Stems several, 70-200 cm tall, hollow, simple,
mostly with some bluish cast, usually hairless below and
crisp-short-hairy to glandular-hairy in the flower cluster.

Leaves: alternate, stalked and slightly reduced upward,
the basal and lower stem leaves often withering. Blades 5-15
cm broad, cleft to the base into 3 main lobes, the side lobes
each again divided not so deeply into 2 main segments. All 5
segments wedge-shaped, irregularly cleft or lobed or toothed.

Flowers: pale blue to whitish, with 5 sepals around 4
small petals, many in tall, narrow clusters up to 35 cm long,
closely flowered, with flower stalks shorter to longer than the
spur. Calyx usually finely crisp-hairy, sometimes glandular-
hairy, deep bluish-purple to nearly white, often streaked with
white, the side sepals 9-15 mm long, rounded to pointed.
Spur 10-15 mm long, longer than the upper sepal. Lower
petals pale to deep blue, the upper nearly white to pale blue.
Flowering time: Late June-August.

Fruits: erect follicles, 10-16 mm long, short-hairy to
glandular. Seeds about 2-2.5 mm long, wing-angled.

Distribution
Along streambanks and meadowland or on moist talus
slopes, montane to subalpine zones, in w. and c. parts of
MT. Also from n.e. OR to CO.

Poisonus plant: see below.

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Contents
Identification
English Names Index
Scientific Names Index
Family Index

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All larkspurs are highly toxic and may be fatal if eaten. Symptoms after ingestion include burning of lips and mouth, numbness of throat; intense vomiting and diarrhea, muscular weakness and spasms, weak pulse, paralysis of the respiratory system, and convulsions. The toxic principles are the alkaloids delphinine and ajacine among others. Toxicity decreses as the plants age, but the seeds are very poisonous. Many cattle have been poisoned by larkspurs.