Cinquefoil or five-fingers, names applied to the spp. with 5 lfls. Hypanthium saucer-shaped to hemispheric; sep (4)5, alternating with as many, usually somewhat narrower or shorter, foliaceous bractlets; pet (4)5, diverse in size and shape; stamens 5-many, commonly 20; pistils inserted on a prolongation of the receptacle, (10-) numerous; ovaries short; ovule 1; style slender, terminal or lateral or nearly basal, articulated with the ovary; fr a head of achenes, often partly enclosed by the persistent, accrescent cal; herbs or small shrubs, with compound, stipulate lvs and small or medium-sized, yellow or seldom white or red-purple fls. x=7; many spp. are polyploid, or apomictic, or both. 200, N. Hemisphere.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.