The Harebell (Campanula rotundifolia) is a short to medium, slender, hairless, rhizomatous perennial in the bellflower family Campanulaceae. In Scotland, it is often known as the Bluebell, whereas elsewhere in Britain, "bluebell" refers to Hyacinthoides non-scriptus. The species is very variable in form. It occurs as tetraploid or hexaploid populations in Britain and Ireland, but diploids occur widely in continental Europe.
The root leaves are dark green, roundish, usually slightly toothed, with prominent hydathodes and may wither early or persist all season. The leaves on the flowering stems become progressively more linear and the upper ones are unstalked. The flowers usually have five-fold symmetry, although other variants are quite frequent. The flowers are usually pale blue, although white, pink and violet variants occur, 15 mm long, borne on long thin stalks either singly or in loose clusters. The petal lobes are short and curve outwards. The flowers are pollinated by bees (see illustration) but can self-pollinate. In common with other Campanulas, all parts of the plant exude white latex when injured or broken. The seeds are produced in a capsule about 3-4mm diameter. The seeds are released by decay of the capsule wall.
Harebells flower in late summer between July and October, sometimes into November, and are found on dry, nutrient-poor grassland and heaths in Britain, throughout Northern Europe and in North America. Once established, the plants compete with tall grass, but the minute seedlings need a clear space in which to establish. The plant often successfully colonises cracks in walls or cliff faces, but is also prominent in dunes.