Pulmonaria, commonly known as lungwort, is a genus of flowering plants in the family Boraginaceae, placed within the subfamily Boraginoideae and the tribe Boragineae alongside its close relative Borago. The genus comprises approximately 10 to 18 species, depending on the taxonomic treatment, and is distributed across Eurasia — native primarily to Europe and western Asia, with one species (P. mollissima) extending east into central Asia.
Members of the genus are evergreen or herbaceous perennials that form low clumps or rosettes, typically reaching 15–25 cm in height and spreading up to 60 cm wide. The plants are covered in hairs of varied length and stiffness. A slowly creeping rhizome with adventitious roots makes up the underground portion. Flowering stems are unbranched, rough, and bristly, rarely exceeding 30 cm. The leaves are one of the genus's most distinctive features: broadly lanceolate to oval, often prominently spotted in silver-white, pale green, or dark markings caused by air pockets beneath the leaf surface that mask chlorophyll.
The flowers are funnel-shaped and characteristically heterostylous — each species produces two flower forms (pin flowers with long styles, and thrum flowers with long stamens). One of the most striking attributes is that the corolla opens pink to violet and matures to blue or violet-blue, so plants in bloom simultaneously display two distinct colors. The inflorescence is a terminal scorpioid cyme, appearing in late winter to early spring.
About eight species are cultivated as ornamental garden plants, particularly prized as groundcover in damp, shaded spots. Pulmonaria saccharata, P. angustifolia, and P. longifolia are the most widely grown, and several cultivars have received the Royal Horticultural Society's Award of Garden Merit.
Etymology
The genus name Pulmonaria derives from the Latin pulmo, meaning lung. Under the doctrine of signatures, the spotted, oval leaves of Pulmonaria officinalis were believed to resemble diseased lungs and were accordingly used in traditional medicine to treat pulmonary conditions. The English common name "lungwort" reflects the same association, as do equivalents in German (Lungenkraut), French (herbe aux poumons), and Serbian (plućnjak); in some East European languages, however, the common name instead derives from a word for honey — for example, Russian medunitza and Polish miodunka.
Distribution
Pulmonaria species are distributed across Eurasia, with the center of diversity in Europe and western Asia. One species, P. mollissima, extends the range east to central Asia. Within Europe the genus is most strongly associated with temperate deciduous woodland habitats.
Ecology
Pulmonaria is an early spring-flowering perennial that retains its leaves through late winter, with new growth emerging just as the old foliage dies back. The heterostylous flowers — opening pink or violet and fading to blue as they mature — are an important early nectar source for bumblebees and other long-tongued pollinators. The distinctive leaf spotting results from air pockets beneath the leaf surface that disrupt chlorophyll expression rather than from pigmentation.
Cultivation
Of the roughly 18 known species, approximately eight are grown as ornamental plants. Pulmonarias are valued primarily as deciduous groundcover for damp, shaded borders, where they produce their bicolor flower display in late winter and early spring. Pulmonaria saccharata, P. angustifolia, and P. longifolia are the most commonly cultivated species; numerous named cultivars exist, several of which hold the Royal Horticultural Society's Award of Garden Merit. Plants are generally easy to grow in humus-rich, moisture-retentive soil in partial to full shade and spread slowly via rhizome.
History
The use of Pulmonaria officinalis in European herbal medicine dates to at least the medieval period, when the doctrine of signatures guided plant selection: the spotted leaves were interpreted as a divine sign that the plant could treat lung diseases. The genus was formally named by Linnaeus, retaining the medieval Latin pulmonaria already in use by earlier herbalists.
