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

General:
Perennial herb from a short, freely rooted, densely scaly rhizome; stems erect, solitary, glandular and sometimes hairy, especially above, 20-60 cm tall.

Leaves:
Basal leaves numerous, 5-15 cm long, 1-4 cm wide, stalked, lanceolate to oblanceolate, 3-5 veined, sparsely to densely hairy and glandular, entire to remotely toothed, often with white or brown woolly tufts at the bases, stem leaves similar, 2-4 pairs, reduced upwards.

Flowers:
Heads with ray and disk flowers, solitary, sometimes 2-3, the bases moderately to densely hairy and glandular; involucres 12-20 mm tall; involucral bracts lanceolate to oblanceolate or elliptic-oblong, long-hairy, often sparsely so above, the tips fringed within; ray flowers orange-yellow, 11-23, with 3 blunt teeth; disk flowers yellow, with spreading white hairs among the stalked glandular hairs or the white hairs few or lacking.

Fruits:
Achenes 4.0-5.5 mm long, densely, stiff-hairy; pappus white, finely-barbed.

Notes:
Arnica sororia has always been treated as a distinct species from A. fulgens. The former, however, is so closely related to the latter that the only consistent difference is the pubescence on the disk corollas (Tayl. and MacBryde 1978, Douglas 1982). I have thus treated the two taxa at the varietal level.

1. Disk corollas with spreading white hairs among the stalked, glandular hairs; old leaf bases often with dense tufts of long, brown-woolly hairs in the axils................................................ var. fulgens

1. Disk corollas without, or occasionally with a few spreading white hairs among the stalked glandular hairs; old leaf bases with only a few, if any, long white hairs in the axils.......................................... var. sororia (Greene) G.W. Dougl. & G. Ruyle-Dougl.