- Name also: Red Whortleberry, Lingonberry, Mountain-cranberry
- Family: Heather Family – Ericaceae
- Growing form: Perennial dwarf shrub. Rhizomatous.
- Height: 5–30 cm (2–12 in.). Stem ascending–erect, sparsely branched, woody, hairy.
- Flower: Corolla bell-shaped–cup-shaped, white–reddish, 5–8 mm (0.2–0.32 in.) long, fused, 4-lobed. Sepals 4. A single carpel, protruding from flower. Stamens 4 or 8. Inflorescence a short, dense terminal raceme; flowers nodding.
- Leaves: Alternate, short-stalked, overwintering. Blade broadly elliptic–obovate, tips quite tapered–notched, leathery, dark green and shiny on top, underside light green and dark-speckled, margins entire–obscurely crenulate, lateral veins clearly distinct.
- Fruit: Spherical, 5–8 mm (0.2–0.32 in.) long, red, shiny, juicy, sweet, quite acidic berry.
- Habitat: Dry, young and grove-like forest heaths, swamps, bogs, rocks, fell moors, field banks, roadsides.
- Flowering time: June–July(–August).
Cowberry is abundant, especially in dry, light-filled forest heaths – it is the type species of the vaccinium-type forest according to the Finnish forest site type classification system. Cowberry is one of Finland’s most cherished and collected fruits of the forest, and it is gathered for domestic use and commercially too. The annual harvest varies from one to 20 million kilos, but even so up to ten times that amount are left undisturbed in the Finnish forests. Apart from people, many forest animals are interested in cowberries: the bear is probably its most famous fan, but even hunters like wolves and pine martens like the berries as an accompaniment to their meat. An especially good cowberry harvest can delay the migration of birds and forest heath thrushes only leave after the plants have been covered in snow. A bumper crop is inevitably followed by a poor one: a heavy crop saps the plants’ power and they flower weakly the following year and do not produce much fruit. Compared to bilberry, however, the cowberry crop is more reliable: cowberry flowers a couple of weeks later when the weather is more stable and there are usually more insects around. The most important pollinators are bees – both bumblebees and honey bees – although many other insects, from flies to beetles, also visit the flowers.
Cowberry’s aerial shoots only live for a few years, and individual roots can live for a couple of decades, but the plants themselves can be hundreds of years old: as the oldest parts rot, the top keeps growing and pushing out new shoots. The age of the plant can be estimated from its size: the patch grows about 10 cm (4 in.) per year, and the largest patches can in fact be comprised of a single plant. Cowberry is pretty fire-resistant and is not destroyed by logging either, so the dwarf shrubs can be older than the forest they are growing in.
Cowberry can be confused with bearberry (Arctostaphylos uva-ursi), whose leaves are obovate with spineless undersides, and whose berries are dry, floury and unfit to eat. Both retain their leaves throughout the winter, unlike bilberry, which sheds its.