It is a short-lived herbaceous perennial or biennial growing to 12–30 cm (5–12 in) tall by 15 cm (6 in) wide, with hairy leaves and a profusion of disc-shaped, intensely blue (occasionally white) flowers in Spring.
Stace describes this plant as having the following characteristics:
- Upright, to 50 cm; softly hairy, with hairs at more-or-less right-angles to the main stem.
- Flowers grey-blue, to 8mm across, flat in profile; sepal tube with hooked hairs; April–July.
- Mature fruit dark brown, shiny.
- Mature calyx on spreading stalks longer than sepal tube; calyx teeth spreading to expose the ripe fruit.
- Basal leaves stalked, in a rosette; upper leaves not stalked.
- Generally found in woods, scree and rock ledges; common throughout the British Isles.
Widely cultivated throughout the temperate world, it is particularly associated with spring bedding schemes involving other spring-flowering subjects, notably daffodils, tulips, wallflowers and primulas. It is also the parent of numerous cultivars in shades of pink, blue and white; for instance 'Blue Ball', a compact variety which has gained the Royal Horticultural Society's Award of Garden Merit.
Other cultivars include:-
- 'Blue Basket', a taller variety with deeper blue flowers
- 'Music', erect and large flowered
- 'Pompadour', compact, ball-shaped with large rose-pink flowers
- 'Snowball', white flowers
- 'Ultramarine', dwarf with very deep blue flowers
- 'Victoria Rose', bright pink flowers
- New Flora of the British Isles; Clive Stace; Third edition; 2011 printing
- The Wild Flowers of Britain and Northern Europe; Fitter, Fitter, Blamey; Collins; 3rd edition 1978
- RHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. pp. 1136. ISBN 1405332964.