| Glandora diffusa | |
|---|---|
| |
| G. diffusa, Osaka Prefectural Flower Garden, Japan | |
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Boraginales |
| Family: | Boraginaceae |
| Genus: | Glandora |
| Species: | G. diffusa |
| Binomial name | |
| Glandora diffusa (Lag. ) I.M.Johnst. | |
Glandora diffusa, the purple gromwell, syn. Lithodora diffusa, 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, G. diffusa var. alba, the blue-flowered varieties are most valued in gardens for the intense azure color of their abundant blooms. A number of cultivars have been developed for garden use.
Glandora diffusa is hardy down to −23 °C (−9 °F) (USDA zones 6 - 8), and requires a position in full sun. It needs a well-drained acid or neutral 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.
References
- RHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 978-1405332965.
- ^ Armitage, Allan (1989). Herbaceous Perennial Plants. Athens, GA: Varsity Press, Inc. pp. 385–386. ISBN 9780942375015.
- "results for 'Glandora diffusa'". Royal Horticultural Society. July 2017. Retrieved 6 September 2020.
- "Lithodora diffusa 'White Star' Technical Guide" (PDF). Blooms of Bressingham. Archived from the original (PDF) on 2017-02-24. Retrieved 2017-01-07.
- Coombes, Allen J. (2012). The A to Z of plant names. USA: Timber Press. pp. 312. ISBN 9781604691962.
| Taxon identifiers | |
|---|---|
| Glandora diffusa |
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| Lithospermum diffusum | |