Lungwort, Pulmonaria officinalis. Growing at the base of an east-facing wall in a garden in Kelling, North Norfolk, early April 2018.

Spring has arrived all of a sudden, with record-breaking February temperatures in parts of Britain. While it has been lovely out in the sunshine, the unseasonal weather is distinctly unsettling, with our knowledge that the Earth is expected to experience more record-breaking temperatures this year (note 1).

One result of the extra warmth has been the early appearance of hibernating bumblebees, butterflies (Peacock, Small Tortoiseshell, Comma and Brimstone) and the emergence of some solitary bees. One of these has been Anthophora plumipes, the Hairy-footed Flower Bee, which feeds on spring flowers such as Primroses, ‘Bowles’ Mauve’ Wallflowers and Lungwort.

Lungwort, Pulmonaria officinalis, normally starts to flower in March and continues through to May.  It’s a slow-growing perennial plant and has characteristic white spots on its leaves. Like Oysterplant, it is a member of the family Boraginaceae. Unlike Oysterplant, you won’t find it on a beach but in a garden or naturalised in woods, scrub or on waste ground. Lungwort has purple flowers, which start off pink, like several other members of its family.

In the British Isles the plant is an introduction, but it occurs widely in the wild in continental Europe. The plant prefers fairly open shade, a reasonably moist but not waterlogged soil and not too much summer heat. It is hardy to UK hardiness zone H4 (-10ºC to -5ºC). Lungwort flowers lack scent, but bees still are able to find them, possibly (with the ability to see ultraviolet light) as “incandescent beacons, shining like lamps in the semi-shade” (note 2).

The article “Biological Flora of the British Isles: Pulmonaria officinalis” is well worth a read (note 3). It snappily describes the plant as a “distylous, perennial rosette hemicryptophyte“. Distylous means that the flowers come with long and short styles and stamens, rather like pin- and thrum-eyed Primroses. A hemicryptophyte is a plant whose perennating buds are at ground level, the aerial shoots dying down at the onset of unfavourable conditions (such as in the heat of summer).

Like the name Lungwort the scientific name, Pulmonaria, refers to the lungs (Latin Pulmoa) . This is because the plant’s spotty leaves were thought to resemble diseased, ulcerated lungs. The Doctrine of Signatures, used in folk medicine, drew upon the belief that if a natural object looked like a part of the body it could cure diseases that arose there (note 4). Other examples include Liverworts, Spleenwort, Eyebright and Toothwort. The specific name ‘officinalis‘ refers to Lungwort’s use in herbal medicine.

Lungwort leaves have a high mucilage content and have been used externally for the treatment of burns and eczema. Internally, the plant has been used to treat sore throats, as well as chest conditions such as coughs (sometimes in conjunction with Coltsfoot). Lungwort’s phytochemistry has only been investigated very recently (note 5).

Lungwort leaves are edible raw or cooked but the plants growing in my dry garden soil need all the leaves they can grow, just to survive, so I haven’t tried them. Besides, the plant doesn’t exactly have rave reviews on the Plants For A Future website. “A fairly bland flavour… an acceptable addition to mixed salads, though their mucilaginous and slightly hairy texture make them less acceptable when eaten on their own“. Cooked, the young leaves “make a palatable cooked vegetable, though we have found the texture to be somewhat slimy.”

I am not alone in recommending Pulmonaria officinalis and other Pulmonaria species as garden flowers: Lungwort was Plant of the Week in The Guardian in March 2017 and featured in The Telegraph in 2002. The RHS also offers advice on growing the plant. Different Pulmonaria flower colours and leaf shapes are available, as are plants with unspotted leaves. My own favourite remains Pulmonaria officinalis and I have fond memories of it growing in gardens in north-east Scotland.

Two other Lungworts grow wild in the British Isles, but are not common and I haven’t seen them (but see Update – May 2019, below). Both are native, unlike Pulmonaria officinalis.

Narrow-leaved Lungwort, Pulmonaria longifolia, grows in light shade in Hampshire, around the Solent and on the Isle of Wight, and in Dorset, near Poole Harbour. It has narrower, oval, bluish-green lightly spotted leaves and smaller, but “piercingly blue” flowers (note 2).

Unspotted or Suffolk Lungwort, Pulmonaria obscura, grows only twenty miles from home, but is confined to three privately-owned Suffolk woods, which are inaccessible by public transport and only seldom open to public visits. Its name comes from the lack of spots on its leaves, but as I haven’t seen it, I think that “Unspotted” is rather appropriate. The lovely NatureGate website has photographs of this lovely plant, which also grows in southern Finland.

Lungwort is also known by other English names, including Mary-spilt-the-Milk (note 6), Lady’s Milk-drops (from the spots on the leaves), Spotted Dog, Soldiers and Sailors, Jerusalem Sage, Bethlehem Sage and Jerusalem Cowslip. I wonder whether the “Jerusalem” and “Bethlehem” names come from the plant’s Easter flowering time, but I have so far been unable to find out.

Notes

Note 1: The article “Media reaction: The UK’s record-breaking winter heat in 2019” on the Carbon Brief website is well worth a read, and includes Met Office diagrams showing how great the maximum daily temperature anomalies have been.

Note 2: I recommend Peter Marren’s very enjoyable book “Chasing The Ghost – My Search For All the Wild Flowers of Britain” (Square Peg, London, 2018). It has some very vivid descriptions of Lungwort flowers, including Pulmonaria longifolia and P. obscura. He managed to see P. obscura in Suffolk, and found that is “not only attractive and grows in a lovely, wild location, but is also reasonably distinctive and not ‘obscure’ at all”.

Note 3: See Sofie Meeus, Rein Brys, Olivier Honnay and Hans Jacquemyn (1992) – “Biological Flora of the British Isles: Pulmonaria officinalis“.  Reprinted in the Journal of Ecology (2013), 101, 1353–1368.

Note 4: The Swiss physician Paracelsus was an important advocate of the Doctrine of Signatures and thought that “Nature marks each growth… according to its curative benefit“.

Note 5: See Krzyzanowska-Kowalczyk J, Pecio L, Moldoch J, Ludwiczuk A, Kowalczyk M. Novel (2018) –  “Phenolic Constituents of Pulmonaria officinalis L.”  Molecules. 2018;23(9):2277. Thanks to the United States National Center for Biotechnology Information for putting the article online.

Note 6: Richard Mabey (1996): “Flora Britannica“, Sinclair-Stevenson, London. Page 306.

Update – May 2019

I have now managed to see both Unspotted or Suffolk Lungwort, Pulmonaria obscura, and Narrow-leaved Lungwort, Pulmonaria longifolia. In early May I helped with a count of plants in two of the woods where Suffolk Lungwort grows, then in mid May I went to see Narrow-leaved Lungwort while staying on the Isle of Wight. Here are pictures, for comparison with our better known spotty friend:

Narrow-leaved Lungwort, Pulmonaria longifolia.

Unspotted or Suffolk Lungwort, Pulmonaria obscura