Biological Flora of the British Isles: Pulmonaria officinalis

This account presents information on all aspects of the biology of Pulmonaria officinalis L. (Common Lungwort) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characteristics, herbivores and disease, history and conservation. Pulmonaria officinalis is a distylous, perennial rosette hemicryptophyte that is naturalized in Britain. It occurs predominantly in the understory of broadleaved, mixed, open woods rich in hornbeam, beech and oak, but is has also been recorded from hedges, banks alongside streams, (sunken) roadsides, built-up areas, gardens, rubbish tips, yew woodland and, less frequently, coniferous woodland. Its native range stretches from southern Sweden, in the north, to northern Italy, in the south, and from western Germany to Poland and Lithuania. It is most common in central Europe. Pulmonaria officinalis reproduces both by sexual and vegetative means. The underground parts consist of a slowly creeping rhizome with adventitious roots. Despite the presence of an elaiosome that is attractive to ants that likely facilitates seed dispersal, populations often show a significant fine-scale spatial genetic structure and small neighbourhood sizes. The leaves and flowering stalks are covered in hairs of varied length and stiffness, and stems and inflorescences are sparsely covered with glandular hairs. Flowers of P.officinalis are heterostylous, with distinct pin and thrum morphs. The corolla varies from purple, violet or blue to shades of pink and red, or sometimes white. The flowers are mainly pollinated by solitary bees and bumblebees. Pulmonaria officinalis has significantly expanded its distribution in the British Isles since the 18th century, especially in southern England. P.officinalis is currently not regarded as threatened in Europe. Nonetheless, small, isolated populations of the species often show reduced reproductive success and lower genetic diversity, potentially affecting their long-term survival. Preservation of local habitat conditions by regular opening of the forest canopy and restoration of gene flow among populations are required to maintain viable populations of P.officinalis in the long term.