Perennial herb from mass of thick, fibrous roots, sometimes fleshy and more or less tuberous; stems usually several, decumbent to erect, 20-60 (100) cm tall/long, somewhat hollow; plants stiff-hairy to less commonly smooth.
Basal narrowly egg-shaped to oblong or semicircular, the blades usually pinnately 3- to 5-lobed or -parted, 3-12.5 cm long, 2.5-14 cm wide, the segments or leaflets undivided or 1- to 2-times lobed or parted, the ultimate segments linear to circular, margins toothed or entire, tips rounded to narrowly pointed, the stout stalks to 25 cm long; stem leaves alternate, shorter-stalked, more deeply divided, the ultimate segments linear.
Inflorescence a few-flowered terminal cyme; flower stalks to 15 cm long; receptacle stiff-hairy; petals 5 or 6, distinct, yellow or red on the back, yellow above, 8-18 mm long, 4-11 mm wide, nectary on upper surface, the nectary scale smooth, 0.5-1 mm long; sepals 5, bent back 1-2 mm from base, early deciduous, often purplish-tinged, 5-11 mm long, 2-4 mm wide, stiff-hairy, soft-hairy or smooth; stamens 50-70; pistils 5-50.
Achenes, several to many in a globe- to egg-shaped head 5-13 mm long, 6-10 mm wide, the achenes broadly egg-shaped, 2.8-4.5 mm long, 1.8-3.2 mm wide, smooth, margins conspicuous and slightly keeled above; beaks persistent, narrowly lanceolate- to awl-shaped, straight, 1.8-4 (5) mm long.
Two varieties are recognized in BC:
1. Petals yellow, tinged with red or purple on the back, usually over twice as long as wide; heads of achenes hemispheric or sometimes globe-shaped, 5-7 mm long................ var. orthorhynchus
1. Petals yellow, not tinged with red or purple, usually less than twice as long as wide; heads of achenes globe- or egg-shaped, 8-13 mm long..................... var. platyphyllus A. Gray
Synonyms and Alternate Names:
Ranunculus orthorhynchus subsp. platphyllus