4a. Amelanchier alnifolia (Nuttall) Nuttall ex M. Roemer var. alnifolia
Shrubs, 1–8 m. Stems 1–20, often colonial. Leaves: petiole (5–)11.7–17.5(–28) mm; blade usually elliptic to oval to suborbiculate, sometimes quadrangular, (20–)33–47(–67) × (14–)24–36(–55) mm, base usually subcordate to truncate, sometimes ± tapering, apex usually rounded to truncate, sometimes acute or mucronate, abaxial surface glabrous or sparsely to moderately hairy, adaxial glabrous or sparsely hairy. Inflorescences (4–)6–11(–16)-flowered, (8–)26–43(–62) mm. Pedicels: proximalmost (5–)8–16(–29) mm. Flowers: sepals (1.7–)2.6–3.6(–4.9) mm; petals oblanceolate to oval, (5.7–)9–14(–18.8) × (2.2–)3.7–5.1(–6.6) mm; ovary apex moderately to densely hairy (or glabrous). Pomes 10–15 mm diam. 2n = 4x.
Flowering May–Jul; fruiting Jul–Aug. Stream banks and shores, lake shores, mountainsides, dry rocky and grassy slopes (northern shrub-steppe), hillsides, woods, thickets, shaded canyons, moist roadsides; 30–2900 m; Alta., B.C., Man., N.W.T., Ont., Sask., Yukon; Colo., Idaho, Iowa, Kans., Minn., Mont., Nebr., Nev., N.Mex., N.Dak., Oreg., S.Dak., Tex., Utah, Wash., Wyo.
Variety alnifolia extends much farther east than any other western shadbush; it is distinguished by its rounded to truncate leaves, hairy ovary apices, and relatively large fruits. The fruits are grown commercially and are an ingredient of the native American food pemmican.