Shrubs deciduous, 0.5–1 m tall, alpine populations usually 10–15 cm tall, much branched, rhizomatous. Twigs terete, puberulous to glabrous. Leaves scattered; petiole ca. 2 mm, puberulous; leaf blade obovate or elliptic to oblong, 1–3 × 0.6–1.5 cm, papery, abaxially glaucous, puberulous, adaxially subglabrous, secondary veins 3–5 pairs, fine veins evident especially abaxially, base cuneate or broadly cuneate, margin plane, entire, with 1 basal gland per side, apex rounded, sometimes retuse. Inflorescences fasciculate, at end of shoot, 1–3-flowered; bracts caducous, 1.5–2.5 mm. Pedicel ca. 5 mm, glabrous. Flowers 4- or 5-merous. Hypanthium ca. 0.8 mm, glabrous; calyx lobes 4 or 5, triangular-ovate, ca. 1 mm. Corolla greenish white, broadly urceolate, ca. 5 mm, glabrous; lobes triangular, ca. 1 mm. Filaments ca. 1 mm, glabrous; anthers ca. 1.5 mm, thecae with 2 spurs, tubules slightly shorter than thecae. Berry 4- or 5-loculed, bluish purple, subglobose or ellipsoidal, with a bloom, ca. 1 cm in diam. Fl. Jun, fr. Jul–Aug. 2n = 24, 48.
Plants forming dense mats or open, extensive colonies; twigs of current season pale green, terete, glabrous or faintly puberulent, not verrucose. Leaf blades usually glaucous abaxially, green to glaucous adaxially, orbiculate, ovate, or obovate to narrowly elliptic, 8-14 × 3-7 mm, membranous, margins entire, surfaces often faintly puberulent, sometimes hairy throughout. Flowers: sepals usually distinct; corolla white to pink, 3-4(-5) mm, lobes 0.3-0.4 mm; filaments glabrous. Berries blue, 6-8 mm diam., glaucous. 2n = 24, 48, 72.
"Low, diffuse or matted, stoloniferous shrubs; lvs deciduous, firm, elliptic to oblong-obovate, blunt, entire; fls all or mostly 4-merous, in clusters of 1–4 from the axils of bud- scales, on pedicels 2–5 mm; sep ovate or triangular, 1 mm; cor pink, ovoid; anthers spurred; fr sweet, dark blue or black; x=12. Circumboreal, s. to n. N. Engl., n. N.Y., and n. Mich. June, July. Most of our plants belong to the circumboreal tetraploid var. alpinum Bigelow, often growing in bogs or muskeg, 1–3 dm, with lvs 10–25 mm and densely hairy on both sides, the frs 4–6 mm. (V. pubescens) In alpine sites we also have the diploid var. gaultherioides (Bigelow) Bigelow, occurring mainly from Greenl. and e. Can. to the high mts. of N. Engl., dwarf and tufted or matted, the glabrous or subglabrous lvs 5–10 mm and the fr 2–4 mm. (V. microphyllum)"
|Bog bilberry, airelle des marécages|
|Airelle des marais||French||CH|