- Family: Brushfooted Butterflies – Nymphalidae
- Subfamily: Browns – Satyrinae
- Wing span: Small, 26–38 mm (1.01–1.48 in.). Females larger than males.
- Wing upper side: Beige or yellowish brown. Forewing apex and sometimes also back corner of hind wing with small and often inconspicuous blotch (black spot, with light beige margin).
- Wing underside: Forewing reddish beige, margin grey. Apex with white-centred eyespot. Light-coloured stripe next to eyespot. Hind wing light brown, margin greyer, row of eyespots parallel to margin (may also be lacking). Leading edge of hind wing with intermittent white stripe on basal side of eyespots.
- Habitat: Bogs, also waterside meadows.
- Flying time: Late June–mid-July.
- Overwintering form: Caterpillar.
- Larval foodplant: Different grasses (Poaceae), sedges (Carex) and cottongrasses (Eriophorum).
The large heath can be found almost all across Finland (quite rarely) except for northernmost Lapland. It always rests with its wings pressed together, which makes the upper side difficult to study without catching it. The species is very much like the small heath and the chestnut heath. The large heath’s hind wings are almost evenly coloured and often have small black eyespots, while the basal part of the small heath’s hind wing is darker than the outer part, and possible eyespots are light-coloured. In the north the large heath can lack the forewing eyespot, in which case it is easy to tell it apart from the small heath. The chestnut heath can be told apart from the large heath by the brownish red and shiny silvery stripes on the margins of its hind wings.