3. Vaccinium pallidum Aiton (lowbush blueberry, hillside blueberry)

V. vacillans Torr.

V. vacillans var. crinitum Fernald

V. vacillans var. missouriense Ashe

Cyanococcus vacillans Rydb.

Pl. 375 c–e; Map 1647

Plants low shrubs 0.2–1.0 m tall. Bark reddish brown to greenish brown, smooth, not peeling, sometimes becoming finely longitudinally ridged with age. Twigs glabrous to moderately hairy, sometimes glaucous, green to yellowish green, becoming brown with age. Leaf blades 20–50 mm long, 10–25 mm wide, relatively thin, sometimes somewhat stiff but not leathery, elliptic to ovate or obovate, the tip sharply pointed or acutely narrowed to a blunt point, the margins entire or with small, nonglandular teeth toward the tip, sometimes slightly thickened or curled under, otherwise glabrous, the upper surface glabrous or sparsely to moderately hairy along the midvein, not or only slightly waxy, usually at least somewhat shiny, the undersurface dull or slightly shiny, glabrous or sparsely hairy along the main veins, occasionally with reddish glands along the midvein, pale green. Inflorescences short racemes, sometimes reduced to solitary flowers, lacking leaflike bracts at the base of the flower stalks but with small, scalelike, reddish bracts on the stalks, these often shed as the flowers develop. Flower stalks 3–8 mm long, with a conspicuous swollen joint at the junction with the flower. Calyx lobes 1.2–1.6 mm long, glabrous, often glaucous. Corollas 4–7 mm long, 2–3 mm in diameter, tubular to narrowly urn-shaped, white to greenish white, often pinkish-tinged, 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 1.5–2.0 mm long. Styles 5–6 mm long, slightly exserted. Fruits 4–6 mm in diameter, blue and glaucous, less commonly white or black, not shiny. 2n=24, 48. April–May, occasionally reflowering in October.

Scattered to common, mostly south of the Missouri River (eastern U.S. and adjacent Canada west to Minnesota and Oklahoma). Mesic to dry upland forests and ledges and tops of bluffs; occasionally also old fields, on acidic substrates.

There is considerable variation in fruit color and pubescence in this species, but formal varieties based upon these characters are not recognized here. Although the yield is often low, the berries are delicious, and this species is harvested commercially in some southern states, including Arkansas. Specimens with white or black fruits are found only occasionally.

Steyermark (1963) discussed specimens determined by earlier botanists as V. tenellum Aiton and correctly dismissed these as misdeterminations of V. pallidum (as V. vacillans). Vaccinium tenellum is mostly restricted to the Coastal Plain and, except for its low stature, does not share many features with V. pallidum. Steyermark also excluded V. pallidum from the Missouri flora, which he considered distinct from V. vacillans. Vander Kloet (1978) studied this complex morphologically and through controlled crosses, concluding that V. pallidum and V. vacillans should be treated as a single taxon under the former name.