General:
Perennial herb from a short rhizome or branched base; stems leafy, erect, numerous, sometimes branched above, glabrate below, sparsely hairy above, 30-60 cm tall.

Leaves:
Basal leaves poorly developed, often deciduous by flowering time; stem leaves opposite, unstalked to shortly stalked, usually 5-7 (sometimes 4) pairs, linear-lanceolate to lance-elliptic, entire or sometimes inconspicuously toothed, 5-15 cm long, 1.0-3.5 cm wide, short-hairy to sparsely glandular.

Flowers:
Heads with ray and disk flowers, 7-20 (rarely as few as 3 or as many as 35), the bases sparsely to moderate hairy and often with dense, stalked glands; involucres 7-12 mm tall; involucral bracts linear-lanceolate to oblanceolate, hairy; ray flowers yellow, 8-13, conspicuously or inconspicuously toothed; disk flowers yellow.

Fruits:
Achenes 4.5-5.5 mm long, subglabrate or with some short-stalked glands; pappus brownish, more or less feathery.

Source:  The Illustrated Flora of British Columbia

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Illustration Source:  The Illustrated Flora of British Columbia

Flower Colour:
Yellow

Blooming Period:
Early Summer

Fruit/Seed characteristics:
Colour: Brown
Present over the Summer

Source:  The USDA

Synonyms and Alternate Names:
Arnica longifolia subsp. genuina Maguire
Arnica longifolia subsp. myriadenia (Piper) Maguire