Amelanchier alnifolia var. pumila

Dwarf shadbush

Shrubs.  Stems1–10, 1–3 m, single-stemmed or in small clumps; twigs glabrous at flowering.  Leaves conduplicate in bud; expanding or fully expanded and unfolded, green, glabrous or sparsely pilose abaxially by flowering; petioles 5–15 mm; blades abaxially pale green, suborbiculate to oval, 1–5 x 1–2 cm, somewhat coriaceous, bases cordate to truncate (somewhat cuneate), margins entire proximally, dentate in distal 1/2 with 3–5 teeth per cm, lateral veins 7–9 pairs, remaining distinct to the margin and not anastomosing, apices rounded or subtruncate, surfaces glabrous.  Inflorescences 4–8-flowered, erect or ascending, 2–4 cm, only proximalmost pedicel subtended by leaf.  Pedicels glabrous, proximalmost 0.6–1.2 cm.  Flowers: hypanthia campanulate, 3–4 mm diam.; sepals recurving after flowering, 3 mm, glabrous adaxially; petals white, oblanceolate, 8–12 x 3–4 mm, not andropetalous; stamens 12–15; styles 4–5; ovary summit rounded, glabrous. Pomes dark purple, glaucous, 8–9 mm diam., sweet.

Flowering May–Jun; fruiting Jul–Sep.

Mountain slopes, plains; 1600–3400 m

Calif., Colo., Idaho, Mont., Oreg., Utah, Wyo.

The most distinctive feature of Amelanchier pumila is that its leaves, pedicels, sepals, and ovary summits are glabrous at all times (with the exception of a few hairs on emerging leaves in some plants).