Lithodora is a small genus of low-growing, evergreen shrubs and subshrubs in the borage family (Boraginaceae). The plants are native to the western Mediterranean basin and eastern Mediterranean fringe, occurring in southwestern Europe, southern Greece, Turkey, and Algeria, where they grow on rocky hillsides and scrubland. Only three species are currently accepted: Lithodora fruticosa, Lithodora hispidula, and Lithodora zahnii.
The genus is characterised by its wiry, bristly stems, narrow leaves, and tubular five-lobed flowers that are typically a vivid deep blue, though white-flowered forms occur. This intensely coloured blue bloom makes Lithodora highly recognisable among Mediterranean dwarf shrubs. Plants are generally mat-forming and stay close to the ground, making them well adapted to exposed, well-drained, rocky substrates.
In 2008 a portion of the genus was segregated into the separate genus Glandora, reducing the number of species retained in Lithodora to the current three. Both genera remain in the family Boraginaceae, order Polemoniales.
Etymology
The genus name Lithodora derives from the Greek words lithos ("stone") and doron ("gift"), meaning "stone gift." This name reflects the plant's characteristic preference for rocky, stony habitats across the Mediterranean region.
Distribution
Lithodora is native to southwestern Europe, southern Greece, Turkey, and Algeria. The genus is confined to Mediterranean climates, growing on rocky hillsides, limestone outcrops, and garrigues at low to moderate elevations.
Cultivation
Lithodora species are popular ornamental plants valued for their intensely blue, five-lobed flowers. They are particularly well suited to rock gardens and raised beds, where the sharp drainage and warm, exposed conditions mimic their native rocky Mediterranean habitats. Plants generally prefer full sun and alkaline to neutral, well-drained soils.
Taxonomy Notes
The genus Glandora was split from Lithodora in 2008, redistributing several formerly recognised Lithodora species into the new genus. After this revision only three species remain in Lithodora: Lithodora fruticosa, Lithodora hispidula, and Lithodora zahnii. Both Lithodora and Glandora are placed in the family Boraginaceae.
