What common name does Lithodora diffusa go by?

Lithodora diffusa is commonly referred to simply as "Lithodora." This name reflects its genus and is often used within horticultural and botanical contexts. Other names in horticulture can sometimes create confusion, but many plants are frequently known by their genus name when the specific epithet is less commonly used.

The other options represent different plants entirely. Hall's Honeysuckle is a completely different species known for its fragrant flowers and climbing habit. Rubus rolfei, or creeping raspberry, is another unrelated plant with a different growth habit and characteristics. Blue Star Creeper is a name associated with another species that serves a distinct role in landscaping. Therefore, the reference to Lithodora as the common name aligns directly with its botanical classification and is the most appropriate choice.