The Latin name of the species purpurocaeruleum means purple and blue, referred to the changing colour of the flowers with the progress of flowering.
Lithospermum purpurocaerula is a bushy plant that reaches on average 20–60 centimetres (7.9–23.6 in) of height, with a maximum of 70 centimetres (28 in). The stem is hairy, erect and unbranched. Leaves are dark green and lanceolate to narrow elliptic, with a prominent midrib on the underside. Flowers are hermaphroditic, funnel-shaped, 15–20 millimetres (0.59–0.79 in) long and 10–15 millimetres (0.39–0.59 in) of diameter, clustered in a racemose inflorescence. The blossoms are purple-reddish, then the color of the flowers turns into a deep blue. The flowering period extends from April to June. The fruits are bright white capsules, 4–5 millimetres (0.16–0.20 in) long, with a glossy surface. They are very hard (hence the genus synonym Lithospermum, meaning "stone seed" for the hardness of these capsules).
These plants occur in dry and warm forests with sparse deciduous vegetation, in the meadows on the edge of the wood, in hedgerows and scrublands. They prefer calcareous soils rich in humus, at an altitude of 0–1,800 metres (0–5,906 ft) above sea level.
- Pignatti S. - Flora d'Italia – Edagricole – 1982, Vol. II, pag. 398
- Tutin, T.G. et al. - Flora Europaea, second edition - 1993