E-Flora BC: Electronic Atlas of the Flora of British Columbia

Prenanthes racemosa Michx.
purple rattlesnake-root (purple rattlesnakeroot)
Asteraceae (Aster family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #23090)

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Distribution of Prenanthes racemosa
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Species Information

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Perennial herb from a slightly thickened taproot; stems erect, solitary, branched above, soft-hairy above, glabrous and glaucous below, often purplish, exuding milky juice when broken, 0.5-1.2 m tall.
Basal leaves oblanceolate to egg-shaped or elliptic, long-stalked, blades toothed to entire, glabrous, 7-40 cm long, 1.5-10 cm wide; stem leaves similar below, middle and lower ones with winged stalks, becoming short-stalked or unstalked and clasping, reduced upwards.
Heads with strap-shaped flowers, numerous in a dense, spikelike inflorescence; involucres 9-14 mm tall; involucral bracts lance-oblong, 10-14, densely stiff-hairy, purplish to blackish; ray flowers pink or purplish.
Achenes nerved, cylindric, glabrous; pappus of yellowish or brownish hairlike bristles.
This species was last collected in 1946 at Dawson Creek.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Dry grassy slopes in the montane zone; rare in NE BC, known only from Dawson Creek and Pouce Coupe; E to PQ and ME, S to IA, WY and CO.

Source: The Illustrated Flora of British Columbia

Synonyms and Alternate Names

Prenanthes racemosa subsp. mulitflora Cronquist

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References