Norway Cinquefoil (Potentilla norvegica)
Also called Rough Cinquefoil, because it has rough hairs all over. This paradoxical cinquefoil has three leaflets rather than five. It grows in waste places and isn’t too particular about soil; this plant grew in the middle of a gravel driveway near Cranberry, where it was blooming in mid-June.
Gray makes this species a variety of P. monspeliensis:
POTENTILLA L. CINQUEFOIL. FIVE-FINGER
Calyx flat, deeply 5-cleft, with as many bractlets at the sinuses, thus appearing 10-cleft. Petals 5, usually roundish. Stamens many. Achenes many, collected in a head on the dry mostly pubescent or hairy receptacle; styles lateral or terminal, deciduous. Radicle superior. Herbs, or rarely shrubs, with com- pound leaves, and solitary or cymose flowers; their parts rarely in fours. (Name diminutive from potens, powerful, originally applied to P. Anserina, from its reputed medicinal powers.)
P. monspeliensis L. Stout, erect, hirsute, 2-1) dm. high ; leaves 3-foliolate; leaflets obovate to oblanceolate, those of the uppermost leaves toothed nearly the whole length ; cyme rather close, leafy; calyx large; stamens 15-20. Open soil, Nfd. to Alaska, s. to D. C., Mo., Kan., and N. Mex. May-Aug. (E. Asia.)
Var. norvegica (L.) Rydb. Less hirsute; leaflets more narrowly oblong, those of the uppermost leaves mostly 3-5-toothed near the end; inflorescence looser. (P. norvegica L.) Similar situations, e. Que. to n. N. E., L. Superior, and northwestw.; occasional on ballast southw. (Eurasia.)