Herbs , perennial, from orange, yellow, or pale brown, slender rhizomes 0.5-2 mm thick. Leaves basal, petiolate. Leaf blade 1-2-ternately compound, 1-2-pinnately compound, or deeply divided; leaflets ovate or triangular, lobed or parted, margins sharply serrate to denticulate. Inflorescences scapose, 1-4-flowered cymes, to 3 cm (9 cm in fruit); bracts absent. Flowers bisexual and staminate (all bisexual in C . trifoliata ), radially symmetric; sepals not persistent in fruit, 5-7, green to white, plane, linear-lanceolate, oblanceolate to obovate or elliptic, occasionally clawed, 4.2-11 mm; petals 5-7, distinct, green, plane or concave distally, either clavate with adaxial nectary at apex or linear with adaxial nectary near base, clawed, 2-7 mm; stamens 10-60; filaments filiform; staminodes absent between stamens and pistils; pistils 4-15, simple; ovules 4-10 per pistil; style present. Fruits follicles, aggregate, stipitate, forming umbel-like clusters, oblong to ellipsoid, sides not veined; beak present or absent, terminal, straight or apically hooked, 0-4 mm. Seeds dark brown to tan, ellipsoid, shiny, often appearing wrinkled. x =9.
Sep 4-7, petaloid; pet none; staminodes 4-7, smaller than the sep, clavate, nectariferous in the hollow summit; stamens numerous, with broad anthers; pistils 3-7, stipitate even at anthesis, narrowed to a short, slender, persistent style; fr follicular; perennial herbs with basal, evergreen, ternately compound lvs and erect, lfless or minutely bracteate scapes with 1-few white fls. 10, N. Temp. and Arctic.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.