The lingonberry is an erect or ascending shrub growing to a height of 5–30 cm. The stems of the plant are woody and hairy. Its leaves are overwintering, tapering, have a waxy surface and are green on top and light green underneath. The lingonberry flowers in June–July. Its urceolate or pitcher-shaped corolla is 5–8 mm in length and either white or reddish. The inflorescence is a dense terminal raceme. The bitter-tasting lingonberry is globose, red and juicy.
The lingonberry grows throughout Finland. It is the most common shrub among the types of forest undergrowth found in Finland. Typical habitats include xeric, sub-xeric and mesic boreal forests. It can also be found in pine or spruce bogs, in herb-rich forests, on rocky outcrops, on tundra heaths and at the edges of fields.
The lingonberry yields the largest crop of all the wild berries. The harvest is more reliable than that of bilberries, as the lingonberry flowers a few weeks later. The weather is more stable at this time and there is a greater abundance of pollinating insects. The lingonberry is most productive in areas where the tree canopy does not block sunlight from reaching lower levels of growth. The most prolific lingonberry plants will often grow in the clearing that remains after final felling or under seed trees. The best berry-picking spots yield 100–500 kg per hectare. The best time to pick lingonberries is from late August to early October.
Lingonberries contain a significant amount of vitamin E. They have the lowest level of vitamin C of all the wild berries, however. The lingonberry is rich in manganese and is also a good source of fibre. The lingonberry is rich in many different types of polyphenols, the potential health properties of which are being researched intensively. It also contains lignans, proanthocyanidins and resveratrol. The amount of resveratrol in lingonberries is similar to that found in the key ingredient of red wine, dark grapes.
Lingonberries have traditionally been used as a garnish for meat dishes. They can be used as an ingredient in berry soups, porridge, casseroles, baked goods and juice. The berry is preserved by freezing, crushing, or boiling to make jelly or jam. Lingonberries contain the natural preservative benzoic acid, which allows the berries to keep well either crushed and kept in cold storage or submerged in water. Berries picked after a frost can be used to make juice.