Pulmonaria officinalis

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Suffolk Lungwort

Pulmonaria obscura

  • Name also: Unspotted Lungwort
  • Family: Borage Family – Boraginaceae
  • Growing form: Perennial herb. Rootstock horizontal, creeping.
  • Height: 15–30 cm (6–12 in.). Stem hairy.
  • Flower: Regular (actinomorphic), approx. 15 mm (0.6 in.) wide. Corolla initially red, finally bluish violet (occasionally white), fused, funnel-shaped, 5-lobed. Whorl of hair in corolla throat. Calyx fused, campanulate (bell-shaped), shallowly 5-lobed, lobes blunt-tipped. Stamens 5. Gynoecium fused, single-styled. Inflorescence a sparsely-flowered, 1-branched scorpioid cyme.
  • Leaves: Leaves on spring flowering shoots alternate; short-stalked–stalkless; blade lanceolate–ovate, hairy. Summer leaves like a rosette, long-stalked; stalk flat, narrowly winged; blade widely cordate, taper-tipped, with entire margin, hairy.
  • Fruit: 4-parted schizocarp. Mericarps kidney-shaped, angular, hairy, reddish brown, tip with light-coloured appendage.
  • Habitat: Broad-leaved forests. Also an ornamental.
  • Flowering time: (April–)May–June.

Suffolk lungwort flowers early in the spring in lush woods, where it competes with hepatica and wood anemone. Its newly opened flowers are light red, changing later to purple and finally virtually blue. The flower takes its colour from an anthocyanin which acts like a litmus test paper and changes colour as the cell fluid becomes more alkaline as the cells age. Ecologists have spent a long time pondering why some flowers change colours as they age. Other flowers that grow wild in Finland that change colour in the same way are, apart from the lungworts, comfrey (Symphytum officinale) and spring vetch (Lathyrus vernus). The reason for the colour change is probably to do with pollination biology: only the freshest flowers have the nectar that the pollinators are interested in, but the older flowers add to the size of the inflorescence and make it look more impressive and thus play a part in attracting insects, even as they age. Considering its early flowering time, lungworts attract an abundance of bees.

Pollinated flowers develop a dark schizocarp, whose carpel has a light-coloured appendage, i.e. an elaiosome, which attracts ants. As they eat it the ants transport the seeds to new growing places. By summer the flowering stem has withered away to nothing, but lungworts that are growing in sunny broad-leaved forests are easy to recognize too by their large, rough summer foliage.

Common Lungwort

Pulmonaria officinalis

Beautiful Suffolk lungwort is sometimes grown in Finland as an ornamental, and in olden times it was used as a medicinal herb in the same fashion as its more southern relative, common lungwort, also called our Lady’s milk drops because of the white spots on its leaves.

Other species from the same family

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