Fraisier américain

Fragaria vesca var. americana Porter, Bull. Torrey Bot. Club 17: 15. 1890; F. americana (Porter) Britton

Leaves green to bright green; terminal leaflet blade ovate or obovate to slightly rhombic, length/width 1.3–1.6, teeth: relative number 0.2–0.6, relative size 1.5–4, terminal tooth longer than adjacent teeth. Flowers bisexual, 12–14.6 mm diam.; hypanthium 11–16.5 mm diam.; petals white, obovate to widely obovate, margins distinct, sometimes distally crenate. Achenes superficial; bractlets and sepals spreading to strongly reflexed; torus carmine, shiny, elongate-conic (often somewhat pointed), easily separating from hypanthium. 2n = 14.

Flowering spring. Open forests, forest edges, clearings, along trails and roadsides, open grasslands, often on steep, rocky slopes and outcrops; 0–1900 m; Alta., B.C., Man., N.B., N.W.T., N.S., Ont., Que., Sask.; Conn., Ill., Iowa, Maine, Mass., Mich., Minn., Miss., Nebr., N.H., N.Y., N.C., N.Dak., Ohio, Pa., S.Dak., Vt., Va., W.Va., Wis.

It is assumed that after the maximum glaciation, this North American subspecies spread from an eastern refugium northeastward to the Gaspé and northwestward to the Mackenzie and Peace rivers (G. Staudt 1999).