2. Vaccinium corymbosum L. (highbush blueberry, swamp blueberry)

Cyanococcus corymbosus (L.) Rydb.

Map 1646

Plants medium to tall shrubs 1–3 m tall. Bark reddish brown to grayish brown, longitudinally furrowed, peeling in thin plates with age. Twigs glabrous to densely hairy, sometimes glaucous, green to yellowish green or reddish green, becoming brown with age. Leaf blades 15–50(–80) mm long, 8–25 mm wide, relatively thin, not leathery, narrowly elliptic-oblanceolate to ovate, the tip usually sharply pointed (sometimes acutely narrowed to a blunt point), the margins entire or with small, nonglandular teeth toward the tip, sometimes curled under, otherwise usually glabrous, the upper surface glabrous, not waxy, dull, the undersurface dull, usually glabrous, pale or glaucous, rarely with a few tiny, yellow resinous glands. Inflorescences condensed, umbellate racemes, lacking leaflike bracts at the base of each flower stalk, but with small, scalelike, reddish bracts. Flower stalks 6–8 mm long, with a conspicuous collarlike joint at the junction with the flower. Calyx lobes 1.5–2.0 mm long, glabrous, often glaucous and/or waxy, rarely with a few tiny, yellow resinous glands. Corollas 8–10 mm long, 4–6 mm in diameter, tubular to narrowly urn-shaped, white to greenish pink, shallowly lobed, the lobes reflexed. Stamens not exserted, lacking spurs at the filament-anther junction, the filaments flattened, hairy along the margins, the anthers tapered to tubules 3–4 mm long. Styles 7–8 mm long, slightly exserted. Fruits 5–12 mm in diameter, blue, not shiny, glaucous. 2n=24, 48, 72. April–May.

Possibly introduced, uncommon, known thus far from a historical, potentially native population in Newton County and a more recent, introduced occurrence in Ste. Genevieve County (eastern U.S. west to Wisconsin, Illinois, Oklahoma, and Texas). Dry upland forests on ridgetops, thus far only on sandstone substrate.

This species is an important fruit crop in the eastern and midwestern United States. More than 50 cultivars have been released, some with very large and juicy berries. At the site in Ste. Genevieve County, plants apparently became naturalized from adjacent plantings at homesites. The berries are eaten raw, cooked in pies, jams, and jellies, and dried for future use. Three distinct polyploid groups are known, and hybridization with V. pallidum is said to occur (Vander Kloet, 1988).