Columbia monkshood (Aconitum columbianum) is a native perennial found in States west of the Rockies, South Dakota, Iowa and British Columbia at elevations of 2,000 to 9,500 feet. The habitat of this member of the Buttercup Family is wet mountain meadows, forests and stream banks.
A variable plant, Columbia monkshood grows erect or adopts a more vine-like attitude. The branched, hollow stem arises from a tuber. The alternate leaves are palmately divided into 3 to 5 lobes. The upper cauline (stem) leaves are smaller than those leaves nearer the base of the plant.
The Columbia monkshood inflorescence is an open panicle (branched and blooming from the bottom) or a raceme (unbranched and blooming from the bottom). The purple to lilac (occasionally white) flowers are composed of five sepals. The upper sepal forms a “hood” over the flower, much like the cowl of a monk’s habit – thus the common name. The two lateral sepals are rounded and the two bottom sepals are lance shaped. The inconspicuous petals are “hidden” under the hood. The flower has numerous stamens and 3 to 5 pistils.
The fruit of Columbia monkshood is a pod that splits open at maturity to release many black seeds.
Columbia monkshood flowers are specialized for bumblebee pollination. The bees manipulate the flowers to reach the nectar concealed within the flower and in doing so transfer the pollen between plants.
The genus name, Aconitum, is the ancient Greek word for plants in this group and is roughly translated as “unconquerable poison”. All parts of the plant, particularly the tubers, are highly poisonous, especially to livestock. Alkaloids found in monkshood paralyze the nerves, lower blood pressure and reduce body temperature. A drug derived from monkshood, aconite, is used as a sedative. Aconite also appears in historical fiction as a poison. For example, fans of the Brother Cadfael mystery series by Ellis Peters might remember deaths caused by aconite.
Columbianum, or a variation thereof, as the species name indicates “of western North America”. Another common name for A. columbianum is western monkshood.
These Columbia monkshood plants were photographed along the Pacific Crest Trail in the Warner Valley (CA) near Drakesbad.