Mertensia lanceolata, known as prairie bluebells, lance-leaved bluebells, lance-leaved lungwort, and narrow-leaved languid ladies is a species of flowering plant native to the Rocky Mountains and areas of the northern Great Plains in western North America.

Mertensia lanceolata is a variable species with flowering individuals typically growing 10–45 cm in height.

[3] He described the place of collection simply as "In Upper Louisiana," and noted a resemblance of the flowers to those of Pulmonaria paniculata.

It was correctly identified as part of Mertensia and given its present name by Augustin Pyramus de Candolle in 1846.

lanceolata by having the sepals nearly divided to the base and having pollen bearing structures (the anthers) that are longer than the stalks that support them (the filaments).

[14][5][1][8][20] Mertensia lanceolata grows in the Rocky Mountains from northern New Mexico in the south to Alberta in Canada, including Colorado, Wyoming, Utah, and Montana.

[14][21] They grow in a variety of habitats including in forests, the edges of woodlands, stream banks, prairies, rocky hillsides, and alpine tundra.

At that time they found the species to be vulnerable (S3) in Saskatchewan and imperiled (S2) in Alberta, Manitoba, and Nebraska.

They assessed it as apparently secure (S4) in Wyoming and did not evaluate it at the state level for the rest of its range.

[22] Narrow-leaved languid ladies are valued by wildflower gardeners for its dainty vibrant blue flower display and long season of blooming when moisture is good.

[9] It is also rated as with the lowest possible flammability for landscaping to create defensible space by Colorado State University Extension.