Deerberry is an irregularly branched shrub, rarely more than 6 feet high. A blueberry relative, it bears edible blue fruits.
Leaves are alternate, simple, ¾–2¾ inches long, ½–1 inch wide, slightly broader above the middle; the tip pointed; the base narrow, rounded; the margin entire, fringed with hairs; the upper surface dull, light green to yellow green, mostly smooth; the lower surface duller and hairy,with conspicuous veins, hairy; the leaf stalk is very short. Note that small leaves (bracts) are present at the base of the flower and fruit stalks.
Bark is gray to brown, rather smooth, split into long, narrow, papery strips with loose margins; the inner bark is reddish brown; the wood is soft, fine grained, white to pale brown.
Twigs are slender; the growth of the current year is green to reddish, hairy; later, it becomes green to brown and smooth.
Flowers April–June, in loose, hanging clusters with 3–10 flowers; flowers white, sometimes purplish-tinged, broadly bell-shaped, wider than long, about ¼ inch across, 5-lobed, lobed to about the midpoint, lobes spreading; stamens 10, extending beyond the flower.
Fruits July–September, about ¼ inch in diameter, globe-shaped, blue, often with a whitish waxy coating, not shiny, somewhat sweet; seeds egg-shaped, golden brown, finely pitted.
Similar species: Four species of Vaccinium (blueberries) have been recorded as native or naturalized in Missouri. In addition to deerberry, our other native blueberries are farkleberry (V. arboreum) and lowbush blueberry (V. pallidum). The fourth, highbush or swamp blueberry (V. corymbosum), is apparently introduced; it’s uncommon in our state, known from a historical collection of a possibly native occurrence in Newton County, and a more recent, introduced occurrence in Ste. Genevieve County, where fruit plantings apparently escaped from cultivation. It’s an important fruit crop in the eastern and midwestern United States.
Another species, black huckleberry (Gaylussacia baccata), is in the same family as blueberries. Its leaves have numerous tiny, sticky, yellow resin dots (glands), at least on the undersurface, and its fruits (technically drupes, not berries) are leathery with 10 seedlike nutlets (whereas blueberries are berries with numerous seeds). It is critically imperiled in Missouri and known (for certain) only from a few sites in Montgomery and Perry counties.