Kingdom Plantae Family Boraginaceae Scientific name Lithodora diffusa Rank Species | Order (unplaced) Genus Lithodora Higher classification Lithodora | |
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Similar Lithodora, Lithospermum, Boraginaceae, Glandora, Coleonema pulchrum | ||
Lithodora diffusa bumblebees favorite
Lithodora diffusa (purple gromwell), syn. Lithospermum diffusa, is a species of flowering plant in the family Boraginaceae. It is a mat-forming perennial growing to 15 cm (6 in) tall by 60 cm (24 in) or more wide, with dark green, hairy evergreen leaves and masses of blue or white 5-lobed flowers. It is suitable for cultivation in a rock garden or alpine garden.
Although there is a variety with white flowers, L. diffusa var. alba, the blue-flowered varieties are most valued in gardens for the intense azure color of their abundant blooms. Numerous cultivars have been developed for garden use, of which 'Grace Ward' and 'Heavenly Blue' have gained the Royal Horticultural Society's Award of Garden Merit.
Lithodora diffusa is hardy in USDA zones 6 - 8, and should be planted in full sun to partial shade. It needs a well drained soil, as it is susceptible to root rot. It requires vernalization to flower.
The Ancient Greek term lithodora literally means "stone gift", referring to its preferred habitat. Diffusa means "spreading", and refers to the plant's growth habit.
