- Latin synonym: Arctous alpina, Arctous alpinus
- Name also: Mountain Bearberry, Black Bearberry
- Family: Heather Family – Ericaceae
- Growing form: Perennial dwarf shrub. Mat-forming.
- Height: 5–10 cm (2–4 in.), branches limp, up to 50 cm (20 in.) long. Stem woody.
- Flower: Corolla urceolate (pitcher-shaped), white, 3–5 mm (0.12–0.20 in.) long, fused, shallowly 5-lobed. Sepals 5. Stamens 10. A single carpel. A 2–5-flowered raceme terminating shoots, short-stalked. Flowers before leaves emerge.
- Leaves: Alternate, withering before winter, but only falling the following autumn. Blade obovate, 2–4 cm (0.8–1.6 in.) long, serrate, thin, strongly net-veined.
- Fruit: Spherical, 9–12 mm (0.36–0.48 in.) broad, initially green–red and dry, later a black, shiny and juicy berry when ripe.
- Habitat: Fell moors, dry mountain birch and pine forests, sometimes mossy hummocks at the edge of bogs.
- Flowering time: June.
Of the true fell shrubs that grow in Finland, Alpine bearberry grows the furthest south – even on the country’s southernmost fell, Iso-Syöte, in Pudasjärvi. It is often the only representative of the fell species that grows on top of forested hills. Further north it is often the first fell species to greet climbers making their way to the top.
Like Finnish forest trees, Heather family plants form a symbiotic relationship with fungus roots: the plants receive better nutrition from the soil through the fungus – especially phosphorous – and the fungus gets assimilation products, carbohydrates. Heather family plants usually team up with sac fungi (Ascomycota), but alpine bearberry and bearberry live with familiar edible mushrooms.
Unlike its evergreen relative bearberry, alpine bearberry’s leaves wither and die in the winter. The species’ autumnal blaze of flaming crimson is one of the most impressive end-of-summer shows, along with dwarf birch, blueberry and bog bilberry. Withered reddish brown leaves don’t fall but stay in the branch, protecting the plant’s buds: not from the cold but rather from growing too early in the event of a particularly warm late winter. Bearberry and alpine bearberry can be easily told apart on the basis of their flowers, but the plants do not bloom long on the fells. White, urceolate (pitcher-shaped) flowers burst out from behind last year’s withered leaves as soon as the snow has melted and the ground is very wet. In autumn the fruits of pollination appear in the shape of shiny black berries. Most of the crop is eaten by Lapland birds, which spread alpine bearberry’s seeds, but they are also a sweet treat for autumn ramblers too.