Saxifraga oppositifolia – April 14th 2025
Very few flowering plants can grow at temperatures below 5 oC, but this one can. In the Swiss Alps it grows near the summit of one of the tallest mountains, the Dom (4,505 metres above sea level). It was found growing there there in 2009 by mountain guide, Jürg Anderegg, only 40 metres below the summit. Christian Körner, an Austrian ecologist known to many of us in the Botanical Society of Scotland, reported this remarkable discovery and claimed it as ‘the highest flowering plant in Europe’.
Image by Scottish artist William Catto (1843 – 1927), from Aberdeen Art Gallery and Museums Collections. The flower colour seems to have faded (see images below).
It is also found in northern Greenland at Kaffeklubben Island (‘Coffee Club Island’), a place reckoned to be the ‘undisputed northernmost point of land on Earth’. As expected from such a northerly location (83.66 oN) the island is very cold: in the warmest month (July) the average maximum is 3 oC and the minimum is 1 oC. The winter averages are below -20 oC. Quite many bryophytes and lichens grow there, but very few flowering plant species.
Showing the typical form of the plant, only 2-4 cm tall; individual shoots can be fertile (with flowers) or sterile (without flowers). The plant is rooted in shallow soil that has collected in cracks between rocks. Image: Richard Milne.
Readers who walk the Scottish mountains will be familiar with the plant. It is one of the earliest to flower in the spring, and one of the most attractive. Gardeners will know it too: it is much-prized and now flowering profusely in many Scottish rock-gardens. It likes lime-rich soils, and is normally seen as a sprawling cushion on rocky outcrops. But you don’t need to be a mountaineer to see it; it can be found near sea level at many locations throughout the west of Scotland, for example the Mull of Kintyre. In the north, it can be found at the mouth of the River Naver and there are a few near-sea level sites in the East of Scotland, such as the bridge over the River Avon at Ballindalloch in Moray.
Close-up of flowers. They are solitary on stems 1-2 cm which are less densely leafy than the sterile ones. The petals are 6-10 mm. Image: Chris Jeffree.
The Purple Saxifrage is a long-lived native perennial, often forming cushions on rock ledges but it can also be prostrate and trailing. The flowers are rosy purple and pollinated by insects, forming seeds quite readily in Scotland. The leaves are sessile, opposite, and in four rows. They have bristles on the margins of the leaves. At the apex of each leaf there is a single lime-secreting gland (but up to three per leaf in populations outside Britain).
Close-up, showing the bristles on the margins of the leaves. Image: Richard Milne.
The global distribution of S. oppositifolia is circumpolar – it forms a ring in the high arctic, extending southwards in well-separated mountainous areas. Richard Abbott and others used molecular techniques in an attempt to reconstruct the pattern of migration over the last three million years. Based on on restriction fragment length polymorphisms (RFLPs) of chloroplast DNA, they found two distinct clades, one described as Eurasian and the other North American. It was thought that the first arctic occurrence of the species was at the point where Alaska meets Russian, now the Baring Strait but once a land bridge (Abbott et al. 2000). Thereafter, populations diverged, traveling east and west, giving rise to the two clades.
British and Irish distribution of S. oppositifolia, from BSBI/Maps.
A more recent paper presents a different view. The authors had more samples and somewhat more refined analytical methods; they came to different conclusions. They suggested that the ancestral areas of the two lineages are in Europe (likely the Alps) and Central Asia (Winkley M et al. 2012).
Global distribution of S. oppositifolia, from the Global Biodiversity Information Facility (GBIF).
Turning to the ‘older’ literature (pre-dating molecular approaches), we find dfferent viewpoints regarding variation within the species:
“A polymorphic species with several geographical subspecies and numerous varieties, showing also much phenotypic plasticity, but much less variable in Britain than elsewhere. The above description is based on British material and does not take into account the entire range of variability of the species. Our populations belong to the subsp. oppositifolia”
The quote comes from Jones and Richards (1956) and refers to British populations, but other authors explain a wider variation in plants collected from other parts of Europe. In Norway, there are prostrate plants they call S. oppositifolia ssp. reptans and cushion-plants called S. oppositifolia ssp. pulvinata (Brysting et al 1996). Also the chromosome number can vary, being either 2n = 26 or 2n = 52 (Brysting et al 1996).
Purple Saxifrage is the official flower of the Nunavut, the most northerly part of Canada. Readers may like this quote from the Nunavut website:
“The purple saxifrage plays a number of roles in Northern culture. The full blooming of the flowers indicated the time of year when young caribou are being born out on the land. The flowers of the purple saxifrage have a sweet taste and are eaten especially in communities where berries are not abundant. When eaten, the flowers can help relieve gastric problems, but, as with all herbal remedies, if eaten in excess can cause complications. The stems and leaves can be used to make tea. According to many Nunavummuit, the tea is best later in the season after the flowers have died. In times when tobacco was a valued commodity, the stems and leaves were often added to store-bought tobacco. As one of Nunavut’s hardiest and most reliable plants, it is fitting that the purple saxifrage has been chosen as its Floral Emblem”.
References consulted
Abbott RJ, Smith LC, Milne RI, Crawford RMM, Wolff K and Balfour J (2000). Molecular analysis of plant migration and refugia in the Arctic. Science 289, 1343-1346.
Abbott RJ and Comes HP (2004). Evolution in the Arctic: a phylogeographic analysis of the circumarctic plant, Saxifraga oppositifolia (Purple saxifrage). New Phytologist 161, 211-224.
Abbott RJ (2008) History, evolution and future of arctic and alpine flora: overview. Plant Ecology & Diversity 1, 129-133.
Brysting AK, Gabrielsen T M, Sørlibrâten O, Ytrehorn O and Brochmann C. (1996). The Purple Saxifrage, Saxifraga oppositifolia, in Svalbard: two taxa or one?. Polar Research, 15(2), 93-105
Crawford RMM, Chapman HM, Abbott RJ and Balfour J (1993) Potential impact of climatic warming on Arctic vegetation,Flora,188, 367-381.
Jones V and Richards PW (1956) Saxifraga oppositifolia, L. Journal of Ecology 44, 300–316.
Körner C (2011). Coldest places on earth with angiosperm plant life. Alpine Botany. 121, 11–22. doi:10.1007/s00035-011-0089-1. S2CID 22796093.
Winkley M, Tribsch A, Schneeweiss GM, Brodbeck S, Gugerli F, Holderegger R, Abbott RJ and Schönswetter P (2012) Tales of the unexpected: Phylogeography of the arctic-alpine model plant Saxifraga oppositifolia (Saxifragaceae) revisited. Molecular Ecology 21, 4618-4639.
©John Grace
