This species is a native of south-western Europe. It was introduced as an ornamental into British gardens before 1700 but escaped into the wild shortly after that, and over the years became naturalised and widespread. Now it can be seen thriving and flowering beautifully in many parts of the British Isles, and it is still expanding its range. It’s a long-lived perennial and its habitats include woodland, hedgerows and gardens. It is often near human habitation (more about that later).
It belongs to the Boraginaceae, the family that includes Comfrey, Borage, Lungwort and Forget-me-not. You can check the characters of this family and see examples on our LEARN page or simply click on https://www.youtube.com/watch?v=BA2XdNiUiEo. Members of the Borage family tend to be rough-leaved, hairy with bristles, and with blue flowers. The blue in this family is much-admired – the flower buds are often pink but the mature flowers have the truest blues in the entire plant kingdom. Photographs rarely do justice to the borage blues – you have to see these blues with your own eyes. Not surprisingly, borage flowers are sometimes used to decorate cocktails.
I like this plant. It flowers early in the spring and continues for much of the year. The leaves remain green in winter. It is one of the plants frequently spotted as ‘in flower’ in the New Year Plant Hunt. But not everyone likes it. Some consider it to be a troublesome weed. It does have a tough root and much pulling is required to remove it from the soil (people with tender hands must wear gloves to protect from the bristles). Some people are concerned that it invades woodlands, ousting more delicate natives. For example, Stace and Crawley (2015) have pictures of it dominating the floor of a birch woodland in winter, and forming a monoculture on what was once a grassy bank. In Scotland I think it is less likely to invade. I know it from parks, allotments, cemeteries, where it seems to behave itself. Its seeds fall to the ground. They are described as ‘nutlets’ and each flower usually produces four of them. I suspect they stick to muddy boots. Perhaps they are dispersed also by small birds.
Bees like it too. Is it the intense blue that attracts them? How does it appear to bees? I don’t know. But I have seen many wild bees visiting all the members of the Boraginaceae in my garden. They especially go for Viper’s Bugloss (Echium vulgare) and the Gromwell Lithodora diffusa ‘Heavenly Blue’. But on the allotment they love Pentaglottis sempervirens, especially early in the year when there isn’t much else.
Keen to discover its ecological characteristics I searched on the Web of Science and Google Scholar. There is surprisingly little on this species. Like many alien plants it gets a ‘cold shoulder’ from researchers unless they are truly invasive. There are almost no peer-reviewed papers from UK and no PhD dissertations. Books about woodlands fail to mention it. Moreover, I can find very little British or Continental art-work featuring it.
So I looked at the UK database PLANTATT (Hill et al. 2004). The attributes of this plant are listed along with those of many other species. Most of the environmental data for P. sempervirens are unremarkable (it tolerates shade, not too fussy about soil pH or moisture). However, what stands out is its association with soil fertility. For Ellenberg’s Nitrogen it scores 7, whilst the average of all plants in the data base is only 4.4. Amongst the very common plants, P. sempervirens is beaten only by a few, for example: Stinging Nettle (Urtica dioica) and Cleavers (Galium aparine).
Delving further, I looked at the records of this plant along a transect from Glasgow to Edinburgh. From 1987-2019 the species P. sempervirens was mainly recorded in heavily populated areas, especially around Glasgow and Edinburgh. The pattern can be seen in the BSBI maps shown below. The plant is indeed an urban specialist.
I think I see why. It needs highly fertile soil, found where people make gardens. It may well be that nitrogen supply is key. Nitrogen enters plants not only via fertilised soil but also from the atmosphere; one source is the exhaust of motor vehicles, hence roadside verges in built-up areas may be N-rich). Perhaps the excreta of dogs makes a contribution to the fertility of pavement edges. Once established it may be spread from seeds attached to boots, so people who like visiting gardens spread the plant inadvertently.
What about the name of this always-alive (sempervirens) plant? Formerly, it was described and named by Linneaus who called it Anchusa sempervirens. But in 1949 along came the famed American botanist Liberty Hyde Bailey (1858–1954) and he decided it should be in a genus of its own, called Pentaglottis (‘five tongues’) so now we must call it Pentaglottis sempervirens (L.) L.H. Bailey. We are reminded that not all botanists of the 19th and 20th Century were European! Bailey was a significant figure in American botany, famous for three quite disparate achievements: re-discovering Mendel’s work on genetics, research on palms, and the advancement of rural traditions in America.
By the way, have you noticed that the Boraginaceae have all the best Olde English names? Bugloss, Alkanet, Lungwort, Gromwell (is it associated with Cromwell?), Fiddleneck, Comfrey and Forget-me-not. Pentaglottis sempervirens can be called Green Alkanet, Evergreen Bugloss, or Alkanet. The preferred English name is Green Alkanet. Alkanet is a word from medieval times, meaning henna, that’s the dye that can be made from almost any member of the Boraginaceae.
Appendix: local and global distribution maps
References
Hill MO, Preston CD, Roy DB (2004) PLANTATT – Attributes of British and Irish Plants: Status, Size, Life History, Geography and Habitats.https://www.brc.ac.uk/biblio/plantatt-attributes-british-and-irish-plants-status-size-life-history-geography-and-habitats
Stace CA and Crawley MJ (2015) Alien Plants. Collins, London.
Botany in Scotland 