Scotland’s heritage of naturalised medicinal plants

Although much has been written about Scottish plants, there has been no Flora of Scotland as such since Hooker’s Flora Scotica of 1821. Instead British Floras and distribution Atlases have been published. When BSBI’s New Atlas of the British and Irish Flora was published in 2002, introduced plants were subdivided into archaeophytes and neophytes for Britain as a whole, but British natives that were considered to be introductions in Scotland were not subdivided. As a result the specifically Scottish archaeophyte heritage has been neglected. Taken together, Sutherland’s Hortus Medicus Edinburgensis 1683 and Sibbald’s Scotia Illustrata 1684 provide a baseline from which to investigate the history of many species now considered to be naturalised introductions in Scotland. This has enabled them to be divided between archaeophytes and neophytes giving perspective to their heritage, particularly that of former medicinal plants. A table of such species is presented with detailed comment.


Introduction
Over a period of years I have investigated the history of a number of Scottish plants, mainly in connection with my fifty years of fieldwork on the Berwickshire and Roxburghshire floras, some of which are discussed in Living plants from ancient people (Braithwaite, 2014d). Most recently, I have written Patrolling the Scottish Border (Braithwaite, 2020) in which I discuss the history of some species that have migrated north across the Scottish Border.
In BSBI's New Atlas of the British and Irish Flora (Preston et al, 2002), as an innovation, introduced plants were most helpfully subdivided into archaeophytes (introduced before 1500 AD) and neophytes for Britain as a whole. I have been frustrated by this treatment because, as this work encompassed all of Britain and Ireland, British natives that were mapped as introductions in Scotland were not subdivided.
My attention has now been drawn to James Sutherland's Hortus Medicus Edinburgensis (Sutherland, 1683) and Sir Robert Sibbald's Scotia Illustrata (Sibbald, 1684) and it has occurred to me that, taken together, they could provide a baseline to review the history of Scotland's naturalised plants and, in particular, of former medicinal plants. These are very much a part of Scotland's cultural heritage and one that is distinct from the heritage of such plants in England, which has a very different history. I have now completed such a review accessing a variety of other sources to supplement the two early floras.
I have taken the view that the status of arable weeds and casuals that might have been introduced into Scotland before 1500 AD are adequately covered by the New Atlas, and have restricted my attention to other species listed by Sutherland (1683) and Sibbald (1684) that are now regarded as naturalised introductions in Scotland. These comprise plants used by man, primarily former medicinal plants, and some purely ornamental species. Robert Sibbald (1641-1722 was a physician who quickly became a man of influence in Edinburgh. He cultivated medicinal plants from an early age and soon recruited James Sutherland (1639Sutherland ( -1719 to care for his collection. Working with Andrew Balfour the collection was formally established in 1667, was transferred to larger grounds in 1675 as the Edinburgh Physic Garden and in 1699 was moved again on a much larger scale and with increased status as the Royal Botanic Garden Edinburgh, where Sutherland became the first Regius Keeper. Sibbald was intent on following John Ray's Catalogus Plantarum Angliae et insularum adjacentum or 'Catalogue of the Plants of England and the adjacent islands' (Ray, 1670). Sibbald obtained a royal warrant to send out a request for lists of wild plants and animals to suitable individuals all over Scotland (Sibbald, 1682). The response was excellent, given the circumstances in Scotland at the time, and formed much of the basis of his Scotia Illustrata (Sibbald, 1684). It is not without errors and inadequacies, as might be expected given the diverse abilities of the contributors. The book has several sections including Plantis in Scotia sponte nascentibus agit or 'The naturally occurring wild plants of Scotland' and Plantis Scotiae Hortensibus or 'The garden plants of Scotland'. The first of these has recently been translated from the original Latin by Lee Raye (Raye, 2020). James Sutherland was a highly accomplished botanist and gardener, who, after seven years work, could boast that the Edinburgh Physic Garden ranked with the best in Europe. That this was no idle boast is demonstrated by his meticulous Hortus Medicus Edinburgensis (Sutherland, 1683) which lists about 2,000 plants cultivated in the garden.

Sutherland and Sibbald
In his listing of both wild and garden plants, the emphasis of Sibbald's book is on medicinal and other uses. He lists the 'virtues' of each, not separating his own teaching from the many quotations from various herbals. Some species are listed as 'officinal' plants whether or not specific uses are detailed. I have just accepted that both the species with listed uses and the remaining officinal plants might have been introduced around Scotland in the past.
Sutherland's catalogue is more closely structured. He does not list specific uses but instead annotates each relevant species as 'S' for native and 'Offic' for officinal. His introduction explains that officinal is used in the sense of being on the list used for prescriptions that was current at the time.

Project methodology
My main purpose has been to search for Scottish archaeophytes. I have worked through the species listed by Sutherland and Sibbald noting those that one or other or both had indicated uses and that one or other or both considered native but that I would consider as at least possibly introduced. These might well have been naturalised introductions before 1500 AD. I have also considered the ornamental plants listed by Sutherland and Sibbald as under cultivation searching for those that are now naturalised in Scotland and likely to be neophytes.
I then turned to the accounts of the species on my list in Lightfoot's Flora Scotica (1777) and Hooker's Flora Scotica (1821), paying particular attention to the habitats listed (Sibbald gives sparse, and sometimes unconvincing, habitat detail for only a proportion of the species listed). If the habitats listed are ruderal, it strengthens the case for considering a species an introduction.
Next I turned to the species captions of the New Atlas (Preston et al., 2002).
For many of the species on my list it was clear that the account and the status assigned applied as much to Scotland as to the rest of Britain and Ireland. With a few exceptions, I found myself left with the species that are native in parts of England (usually the south) and introductions in Scotland. These I considered individually.
A much wider perspective is provided by Camilla and James Dickson's Plants and People in Ancient Scotland (Dickson & Dickson, 2000). This covers the whole period from the Neolithic to the Medieval detailing the archaeological evidence for the plants used by people for food, clothing and medicine. In respect of my project, it is unsurprising that most of the relevant data had been picked up by the species captions of the New Atlas, such as the medicinal use of two undoubted introductions, Atropa belladonna and Hyoscyamus niger, but the confirmation of medicinal use of Malva sylvestris at Bearsden Fort on the Antonine Wall near Glasgow in the Roman period is especially interesting as the status of the various Malva species has often been debated.
I culled my list further by excluding species which I could accept as native to Scotland, such as Lysimachia vulgaris, or which are not naturalised in Scotland today, such as Leonurus cardiaca.
I have been left with 84 species to consider in depth. These are listed in Appendix 1 at the end of this paper, alongside comments and supporting references where applicable. For the genus Symphytum, similar, but previously unpublished, information is presented below.

Symphytum species as medicinal plants
Comfrey was used over a long period across much of Europe as a medicinal plant. Extracts of the leaves and roots were used internally to encourage broken bones to set and were used externally to promote the healing of open wounds. The dried roots were sometimes ground to make a coffee substitute. The species most used was Symphytum officinale, but other species seem to have been used locally, especially S. tuberosum for which there is support on a number of websites, though I have failed to find an authoritative reference.

Neither Sutherland nor Sibbald claim S. officinale as a native. Its status in
Scotland is difficult to fathom. The cream-flowered variety is unambiguous, but it seems to be found only as vegetative patches in widely scattered localities, as at Amelishope NT3016 and Kirkhope Linn NT3823, where it could be a long-established cast-out. Records for the purple-flowered variety are numerous. The early records, as 'var. patens', almost certainly relate to S. x uplandicum before its identity was understood. The more recent records are more problematic. I have found that if one examines a population of S. x uplandicum one often finds much variation in the characters used to separate the two parents. In particular one can find specimens with the strongly decurrent leaves of S. officinale. I once took such a specimen to the herbarium of the Royal Botanic Garden, Edinburgh and worked through the Scottish specimens in the folder for S. officinale. The relatively few cream-flowered specimens were all satisfactory. A few of the purple-flowered specimens with weakly decurrent leaves were obvious errors for S. x uplandicum. The remainder were problematic. My hunch was that most of them were errors for S. x uplandicum, as they had much in common with the specimen I had taken with me, but I was unable to be sure of this.
My opinion is thus that S. officinale is a scarce introduction in Scotland and that the records in the BSBI Distribution Database (https://database.bsbi.org/) include many errors. Some of the introductions appear to relate to an early date, making the species an archaeophyte in Scotland.
Sutherland includes S. tuberosum in his 1683 catalogue for the Edinburgh Physic Garden. John Hope observed the plant nearby naturalised by the Water of Leith in 1765 where Thomas Yalden also observed it in about 1775 (Pearman, 2017) suggesting that it was brought into cultivation in Edinburgh not long before. It seems inescapable that the species was passed around fairly widely soon afterwards. This hypothesis is supported by records from two eighteenth-century walled gardens in the Scottish Borders. In 2007, I was with a party from the Berwickshire Naturalists' Club on a visit to the fine walled garden of Torwoodlee House NT4738, an eighteenth-century mansion near Galashiels. There was a strong colony of S. tuberosum in an uncultivated area. The garden is situated just above the Gala Water and field records follow down the Gala and thence to the River Tweed, where it has colonised the river banks. The walled garden at Thirlestane Castle, Lauder is another case in point. In 2012, I found a strong colony of S. tuberosum by a runnel immediately below the walled garden NT5348. The runnel runs into the Leader Water and again S. tuberosum is naturalised from there to the River Tweed where it is now plentiful on the banks.
The wide ongoing colonisation of the east of Scotland and the Central Belt suggests a series of similar events. On that basis S. tuberosum is a neophyte in Scotland and, indeed, in Britain as a whole.

Status changes from the New Atlas proposed by this paper
The status changes proposed in Appendix 1 may be summarised as follows. Ornamental plant considered to be a neophyte in much of Scotland, but possibly locally native: Myosotis sylvatica.
Ornamental plant considered to be a neophyte in Scotland: Geranium lucidum.
Other species considered to be neophytes in Scotland: Calystegia sepium, Galium album.

Discussion
In the Vascular Plant Red Data List for Great Britain (Cheffings & Farrell, 2005), the editors accept archaeophytes into the class of species to be reviewed for threatened species. They emphasise the cultural and historic importance of archaeophytes. They write: 'Archaeophytes have developed (and exploited) a close relationship with man, which is, in effect, one of commensalism -many archaeophytes are, quite literally, 'followers of man'. The way in which humans now value these species is partly a consequence of having been so intimately associated with them over such a long time period.' Scotland has a different history and culture from England. This has many subtle effects on its flora and fauna, not least on the archaeophytes which are the main focus of this paper. At a time when Scotland's flora lacks a 'Red Data List' of its own, it is hoped that, by drawing attention to the specifically Scottish archaeophyte element of its flora, its conservation may be better informed.
There is no pretence that the lists of proposed archaeophytes presented here are either comprehensive or infallible. The evidence available is often scanty, and even extensive field experience can only hope to expose a proportion of any fallacies. Nevertheless the majority of the proposals are likely to be uncontroversial.
I have inserted a seemingly disproportionate section on the genus Symphytum.
I have done so because the information is unpublished and is a particularly good example of the issues to be addressed in attempting research on archaeophytes.