Polygala calcarea

Polygala calcarea, the chalk milkwort, is a species of flowering plant in the family Polygalaceae, native to western Europe. It is a delicate mat-forming evergreen perennial growing to 5 cm tall by 20 cm broad, with spikes of small, vivid deep blue flowers in spring, and leathery, oval leaves.

Etymology
The specific epithet calcarea means "growing in lime", though this plant will grow in a range of soils.

Cultivation
It prefers sharply drained conditions, and is suitable for cultivation in an alpine garden.

Cultivars
The cultivar 'Lillet' has gained the Royal Horticultural Society's Award of Garden Merit.