Perennial, or occasionally annual, herb from slender, fibrous root mass; stems several, ascending to prostrate, but not rooting at nodes, 20-60 cm tall/long, stiff- or soft-hairy or smooth, somewhat hollow.
Extremely variable, egg- to heart-shaped, 3-lobed or -parted to pinnate, 2-6 cm long, 2-7.5 cm wide, the leaflets undivided or 1- or 2-times lobed or parted, the ultimate segments linear to circular, margins toothed or entire, smooth or hairy, the stalks 3-20 cm long; stem leaves alternate, shorter-stalked, transitional to the upper linear to oblong bracts.
Inflorescence a few- to many-flowered cyme; flower stalks to 15 cm long; receptacle usually smooth; petals 9 to 17, distinct, yellow, oblong to oblanceolate, 7-14 mm long, 2-6 mm wide, nectary on upper surface, the nectary scale smooth, about 0.7 mm long; sepals 5, bent back about 2-3 mm from base, often early deciduous, greenish or reddish-tinged, 4-8 mm long, 2-4 mm wide, soft-hairy; stamens 40-80; pistils 15-40.
Achenes, 15 to 40 in a globe-shaped head 3-7 mm long, 4-9 mm wide, the achenes broadly egg-shaped, 1.8-3.2 mm long, 1.4-3.2 mm wide, about 1/3 as thick, usually smooth, margins distinct, slightly keeled; beaks stout at base, lanceolate, curved, 0.2-0.8 mm long.
Whittemore (1997) speculated that because no collections of this species had been made in BC before 1978, this species should be treated as an introduction. In fact, our first collection was made on Trial Island in 1952. No earlier plant collections are known from Trial Island, but there is no reason to believe it is a recent arrival on the island. Many other rare native species in the Victoria area were not discovered or did not become well known until collection activities increased in the 1960's. This species forms hybrid swarms with R. occidentalis in our area.