Bushy habit, 15-25cm high and wider. Leaves crowded, 6-12mm long, minutely toothed, deep glossy green. Flowers pitcher-shaped, 7-12mm long, bluish-purple to pinkish-purple or lilac much depending on the eye of the beholder being a difficult colour to describe. The dried flowers of the herbarium specimens are bluish, hence the epithet caerulea. Flowering in summer. Circumpolar and mountains farther south at alpine levels, in heathland and rocky places.