Amelanchier alnifolia var. alnifolia
Saskatoon serviceberry, alder-leaved shadbush, saskatoon, saskatoon berry, amélanchier à feuilles d’aulne
Shrubs. Stems 1–20, 1–7 m, suckering and forming colonies or clumped; twigs glabrous after flowering. Leaves conduplicate in bud; usually more than half-grown and unfolded, green, whitish- or yellowish-hairy upon expanding but often glabrous or only sparingly hairy abaxially by flowering; petioles 8–18 mm; blades abaxially pale or glaucous, oval to suborbicular (quadrangular), 2–5 x 2.5–5.5 cm, coriaceous, bases subcordate to truncate (somewhat tapering), margins dentate mostly above the middle with 2–5 teeth/cm or entire, lateral veins 8–13 pairs, remaining distinct to the margin and not anasotmosing, apices rounded to truncate, surfaces glabrous (sparsely hairy). Inflorescences erect or ascending, 3–6 cm, with 5–15 flowers, only the lowest subtended by a leaf. Pedicels sparsely to densely hairy, the lowest 0.5–1.7(–2.6) cm. Flowers: hypanthia shallowly campanulate, 3.5–4 mm diam.; sepals 1.5–3 mm, hairy (glabrous) adaxially, usually recurved after flowering; petals white, oblanceolate to oval, 5–10(–12) x 2–3 mm, not andropetalous; stamens about 20; styles (4–)5; ovary summit rounded, densely hairy (glabrous). Pomes black or purple, 10–15 mm diam., sweet. 2n = 68.
Flowering May–Jul; fruiting Jul–Aug.
Stream banks, river 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., Ont., N.W.T., Sask., Yukon; Colo., Idaho, Iowa, Kans., Minn., Mont., Nebr., Nev., N.Mex., N.Dak., Oreg., S.Dak., Tex., Utah, Wash., Wyo
Amelanchier alnifolia var. alnifolia extends much further east than any other western shadbush,and it is distinguished by its round to truncate leaves that are usually glabrous and well developed at flowering, hairy ovary summit , and large fruits. The fruits are grown commercially and are an ingredient of the native American food pemmican.
Amelanchier alnifolia is thought to hybridize with Sorbus scopulina Greene (x\Amelasorbus jackii Rehder).