A genus of perennial plants of the family Boraginaceae, native to north temperate regions (especially of North America), and having blue or purplish bell-shaped or trumpet-shaped flowers; (also in form mertensia) a plant of this genus.
Notable species of Mertensia include the oyster-plant or sea lungwort, M. maritima, and the Virginia cowslip, M. virginica.
Mid 19th century; earliest use found in John Loudon (1783–1843), landscape gardener and horticultural writer. From scientific Latin Mertensia, genus name (A. W. RothCatalecta Bot I. 34) from the name of Franz Karl Mertens, German botanist + -ia.