Both the common and botanical names of lithodora are variable. Many know it as purple gromwell. The botanical name can be either Lithodora diffusa or Glandora diffusa. Many of the cultivars lack their species name after one of these two genus names. There might be less variety with the cultivars than with the names! Floral color is the primary variable.
White blooming ‘Alba’ is uncommon. After all, lithodora is popular for its rich blue bloom, which ranges from light sky blue to indigo. As the name implies, ‘Blue Star’ flowers have a white edge around a blue center. ‘White Star’ flowers have blue around white. Flowers are tiny but profuse in sunny situations. The dense evergreen leaves are likewise small.
Mature plants are generally only a few inches deep and perhaps two feet wide. They can eventually get more than six feet wide by rooting as they migrate. Although they grow too slowly for large scale ground cover, they work nicely in a sunny atrium, around boulders, or with mixed perennials. Lithodora is susceptible to rot in pots or if watered to frequently.