Vaccinium vitis-idaea (lingonberry or cowberry) is a short evergreen shrub in the heath family that bears edible fruit, native to boreal forest and Arctic tundra throughout the Northern Hemisphere from Eurasia to North America. Lingonberries are a staple in Sweden, picked in the wild and used to accompany a variety of dishes. Vaccinium vitis-idaea spreads by underground stems to form dense clonal colonies. Slender and brittle roots grow from the underground stems. The stems are rounded in cross-section and grow from 10 to 40 cm (4 to 16 in) in height. Leaves grow alternately and are oval, 5–30 mm (0.2–1.2 in) long, with a slightly wavy margin, and sometimes with a notched tip. The berries contain plentiful organic acids, vitamin C, vitamin A (as beta carotene), B vitamins (B1, B2, B3), and the elements potassium, calcium, magnesium, and phosphorus. In addition to these nutrients, they also contain phytochemicals that are thought to counteract urinary-tract infections, and the seeds are rich in omega-3 fatty acids.