Arnica discoidea

Plants 15-60 cm. Stems mostly simple or distally branched. Leaves 3-7 pairs, sometimes crowded at stem bases (basal leaves often persistent on sterile rosettes); petiolate (petioles narrow, 1.5-8 cm, often broadly winged on distal reduced leaves); blades usually ovate to broadly lanceolate, seldom subcordate, 2-12 × 1-7 cm, margins usually serrate to coarsely dentate or crenate, rarely subentire, faces glabrate to pilose, stipitate-glandular. Heads 3-10(-30; erect). Involucres turbinate-campanulate. Phyllaries 8-15, ovate-lanceolate to narrowly lanceolate. Ray florets usually 0 (corollas of peripheral florets rarely dilated, resembling rays). Disc florets 20-50; corollas yellow; anthers yellow. Cypselae dark gray, 6-8 mm, hirsute (hairs duplex) and stipitate-glandular; pappi white, bristles usually barbellate, sometimes subplumose. 2n = 38, 57, 76.

Flowering May-Jul. Chaparral, oak and pine forests; 100-1500 m; Calif., Nev., Oreg., Wash.