The Mountain Plants of Scotland

The speaker at the meeting of the Dumfriesshire and Galloway Natural History and Antiquarian Society (DGNHAS) held on Friday, 8 March 2019, was Dr Carole Bainbridge, a former president of the Scottish Rock Garden Club.  Carole's talk was entitled Mountain Plants of Scotland. In a wide-ranging presentation, Carole described the various mountain plants — or 'Alpines' — growing in different habitats in Scotland. Those growing at the highest altitudes, for example near the summit of Ben Lawers, including the dwarf juniper, (Juniperus communis nana)and the Alpine snowbell (Soldanella alpina) have to cope with strong winds and rapidly changing weather conditions, so they tend to grow in sheltered rock crevices. Many plants growing in these conditions are very short, for example the Mountain Azalea (Rhododendron canescens) grows only 1–2 inches tall.  New species have been added to the Scottish flora comparatively recently, for example a relict population of the pincushion plant (Diapensia laponica), found normally in Alaska and Scandinavia, was discovered in Glenfinnan in 1953. Recently a survey of mountain plants on the inaccessible parts of Ben Nevis has been made, which involved botanists having to learn rock-climbing and vice versa.

Some species prefer short grasslands, at somewhat lower altitude, including club mosses,  the hairy stonecrop (Sedum villosum), mountain avens (Dryas octopetala), and the Alpine moonwort (Botrychium nivalis), which only grows 2 inches high. Longer grass, in areas protected from grazing, is inhabited by the Alpine bartsia (Bartsia alpina), and the Alpine sow-thistle (Cicerbita alpina), the latter being confined to the glens of Angus. Lower still, woodland edges are favoured by various species of orchids, the primrose, and the wintergreen (Orthilia secunda).

The Scottish mountains contain many wet habitats and bogs, and these host species such as the starry saxifrage (Saxifraga stellaris), found on Ben Nevis as high as 1340m. The flow country of the northeast, Scotland's largest area of bog, holds the marsh saxifrage (Saxifraga hirculus), only discovered in 2002, as well as the much more common Cloudberry (Rubus chamaemorus). The insect-eating Sundews also favour boggy habitat.

Paradoxically, some species considered as Alpine or mountain plants occur on the coast in Scotland, especially the north coast, due to the cool climate. For example the mountain milk-vetch (Oxytropis halleri) is coastal in Scotland but a mountain species in continental Europe. Some occur in our area, for example the spring squill (Scilla verna), is common on the Mull of Galloway, while the Pyramidal Orchid (Anacamptis pyramidalis) has been found near Gatehouse of Fleet.

Carole concluded her talk by pointing out that some species have been lost in recent years due to changes in land use and climate change, but given the inaccessibility of many mountain habitats in Scotland it is also likely that there are new species out there waiting to be discovered.

J.H.B.