Lungwort \Lung"wort`\, n. (Bot.)
   (a) An herb of the genus Pulmonaria (P. officinalis), of Europe; -- so called because the spotted appearance of the leaves resembles that of a diseased lung.
   (b) Any plant of the genus Mertensia (esp. M. Virginica and M. Sibirica) plants nearly related to Pulmonaria. The American lungwort is Mertensia Virginica, Virginia cowslip. --Gray.

Cow's lungwort mullein.

Sea lungwort, Mertensia maritima, found on the seacoast of Northern Europe and America.

Tree lungwort, a lichen (Sticta pulmonacea) growing on trees and rocks. The thallus is lacunose, and in appearance somewhat resembles the lungs, for diseases of which it was once thought a remedy.

Source: Webster's Revised Unabridged Dictionary (1913)