Trollius europaeus L., Globeflower
Account Summary
Native, very rare. European boreal-montane.
1896; Mr Pike, of London; Gorminish Island, Lough Melvin.
January to September.
Growth form and preferred habitats
In Britain and Ireland, this rather lovely perennial typically occurs in cool, damp, often shaded habitats, including lake margins, stream and river banks, open woodland or their margins, traditionally managed hay-meadows and rarely on upland rock ledges where the plants may never flower. It needs protection from grazing by sheep and goats to survive. Even when it is not flowering, the large basal palmate leaves of the species are perfectly recognisable. The plant prefers basic soils and is generally associated with limestone districts, and especially in sites where there is some degree of nutrient enrichment from mesotrophic flushing groundwater.
Fermanagh occurrence

T. europaeus occurs, sometimes in considerable quantity, in just one very specialised Fermanagh habitat. It occupies a narrow zone about 2 or 3 m wide, just below the winter high water-mark, on the rocky limestone shores of two of the larger lakes in the county under the light shade and shelter of alder, willow and rose scrub woodland. The species has been recorded from a total of five Fermanagh tetrads on the shores of Rosskit, Gorminish Island and Bilberry Island on Lough Melvin, and from Rushin Point and a couple of nearby sites on Upper Lough Macnean, where it also occurs on the Co Cavan side of the lake (Northridge 1995). RHN has visited the Upper Lough Macnean shore when only the flowers and upper leaves were emergent from the water surface, presumably after a period of heavy May rainfall!
Irish occurrence
Apart from the sites just mentioned, the only other extant Irish stations for T. europaeus are in Co Donegal (H34 or H35 or both?) (three or four sites), although previously it also occurred in Co Leitrim (H29). It might well survive on another, different Bilberry Island, which occurs in Co Leitrim, the one that lies just south of Patrick's Island, but this still needs to be investigated (Northridge 1995).
British occurrence
T. europaeus is a decidedly northern species in the British Isles, being much more common in Scotland and Cumbria than elsewhere. The British distribution is totally confined to the area north of a line between Cardiff and Whitby (R.A. Fitzgerald, in: Preston et al. 2002). This distribution pattern is very similar to that of Cirsium heterophyllum (Melancholy Thistle) (another Irish rarity present in Fermanagh), and in Britain the two species are often associated in damp calcareous grassland (Clapham 1978).
European occurrence
In Europe, T. europaeus is native and widespread throughout N and C regions, but it is absent from most of the westernmost parts of the continent, although widespread and frequent again in the mountains further south from Spain eastwards to Greece (Jalas & Suominen 1989, Map 1557). In Scandinavia, it extends beyond 70°N and it also stretches eastwards to W Siberia (Jonsell et al. 2001), and on the margins of its indigenous distribution, it is occasionally recorded as an established introduction (Jalas & Suominen 1989).
It was been shown by Conolly & Dahl (1970) that the distribution pattern of T. europaeus lies north of the current 27°C maximum summer temperature isotherm, quantifying the basis on which it occurs in Britain and indeed on most of the European Continent. In these areas, it is considered a species of northern or montane to sub-alpine damp, calcareous meadows and pastures, stream banks, the margins of woods and rarely on cliff ledges (Halliday 1997).
Indigenous populations in Scandinavia occupy a rather wider range of habitats than in Britain and Ireland: there it occurs in varying conditions of light, open to moderately shady habitats, on moist to mesic, nutrient-rich soils that are usually refreshed and enriched with moving groundwater. Typical habitats include tall-herb vegetation, scree, fen margins, Willow and Alder thickets, and the banks of water courses. Also in Scandinavia, T. europaeus is closely associated with man-managed 'apophytic' situations, including wooded pasture, forest glades, former hay-meadows, field margins and roadsides (Jonsell et al. 2001). In many of these latter more regularly disturbed stations, T. europaeus, in Scandinavia at least, is recognised as an established introduction, its seed very probably being transported around the countryside by cutting machinery and the hay fodder market.
Decline in range and environmental pressures
In both Britain and Scandinavia, T. europaeus appears to have declined in range over a long period, probably for at least a century. As usual in such situations, decline and retreat is particularly obvious at the margins of the previous distribution. (Halliday 1997; Jonsell et al. 2001; R.A. Fitzgerald, in: Preston et al. 2002). In part, T. europaeus appears to be retreating under pressure from grazing animals, yet like other members of the Ranunculaceae, it contains the blister-inducing bitter toxin protoanemonin, which in theory ought to deter browsers and give the species a measure of protection (Cooper & Johnson 1998). However, further north, Arctic Reindeer are known to graze T. europaeus and other northern representatives of the plant family, and Globeflower seeds are internally transported and occur in reindeer excreta (Ridley 1930, p. 373). The levels of toxin in Trollius may be insufficient to deter deer and other large herbivore species, so it might be possible for cattle, sheep and goats to browse on it without suffering ill effects, again assisting the plant in its seed dispersal. Work is required to investigate these possibilities in Britain and Ireland.
In Britain, the main cause of the obvious decline in the species appears to be the agricultural improvement of land (especially in hilly areas), by drainage, the earlier cutting of herbage for silage than previously for hay, and the widespread application of fertilisers stimulating the growth of more vigorous species with which T. europaeus simply cannot compete (Halliday 1997; R.A. Fitzgerald, in: Preston et al. 2002). In Ireland, populations on or near river and stream banks have also been destroyed by flash floods (eg in Co Donegal), a weather related phenomenon which seems to be increasing in frequency and may well be related to global climate change (Curtis & McGough 1988, p. 100; Sheppard 1991).
Garden escapes and relict status
Globeflower is a longstanding, popular garden border perennial that is undemanding and easy to cultivate. While it must occasionally 'jump the garden fence', as it is claimed it does in Scandinavia (Jonsell et al. 2001), in Britain and Ireland there are only a few stations on the New Atlas map which suggest or indicate such a happening (Preston et al. 2002).
In Ireland, T. europaeus and the other members of the Northern Montane phytogeographical group are regarded as relict plants of past climate stages and much changed environments that are approaching the end of their local occupation (Matthews 1955, p. 117). This understanding fits very well with the restriction in habitat found in Fermanagh, the contraction in range elsewhere, especially in Ireland, and with the developing picture of Global warming (or in our corner of the British Isles, more accurately Global wetting and blowing) (Plantlife Report: Death Knell for Bluebells? Global Warming & British Plants, Anon. 1991).
In view of the large number of apparently suitable sites for T. europaeus on Lower Lough Erne, it is sad to think that the species nowadays appears to show no capacity whatsoever for natural dispersal and colonisation over the relatively short distances involved (8-13 km).
Fossil record
The fossil record is sparse but is sufficient to confirm the native status of Globeflower (Webb 1985). It consists of a tentative Flandrian post-glacial seed record from Ireland of Mesolithic age, and pollen records exclusively from Scotland throughout the entire post-glacial (Godwin 1975).
Sexual reproduction
T. europaeus has a short, stout, erect, fibrous rootstock and it has no powers of vegetative reproduction, instead relying entirely on seed production for increase and dispersal of the species (Clapham et al. 1962).
Insect pollination
Globeflower has a most interesting relationship with three species of small flies belonging to the genus Chiastochaeta. The globular yellow flowers produced from June to August never open their overlapping petal-like sepals, yet despite this (or maybe because of it and the concealment and protection this floral behaviour affords the flower's pollen and nectar food supplies), they are visited by adults of these species of fly which meet, mate and feed on the hidden food sources. Individual Trollius flowers last for only about five or six days and they are self-incompatible. After mating inside one of the closed flowers, the female insects lay their eggs (usually just one per flower).
The Chiastochaeta fly species differ slightly in their sexual behaviour, for example, the stage of flowering at which they lay their eggs, the exact positioning of the eggs, and the paths along which the larvae bore inside the carpels during their development, and in this manner the fly species manage to avoid competition to a remarkable degree, ie strict resource partitioning is present (Pellmyr 1989). The insect species which lays its eggs earliest during the short life of the flower is the one which is most effective in achieving pollination, but this is entirely incidental as far as the insects' movements are concerned.
Flower-insect mutualism
Each flower is reputed to produces a rather large number of ovules (around 400 or so) and only a few young seeds of each flower are eaten by the fly larvae, so the cost to the plant is fairly minimal. This is reckoned to be a fine example of an obligate mutualistic relationship occurring in the temperate zone. Mutualism is a phenomenon that is associated much more frequently with biology in the tropics (Pellmyr 1989). Although there is a cost to the plant, the relationship with these small flies essentially benefits both partners, and the trade-off by the plant of a few of its many seeds enables cross-pollination of its un-opening, self-incompatible flowers.
When fertilised, the numerous carpels of T. europaeus develop into many-seeded follicles, which when ripe split to release the seed.
Seed dormancy and germination
The seed is dormant at dispersal and requires cold-stratification during the following winter to break dormancy (Milberg 1994). Experimental germination was equally effective in both light and dark treatments, which suggests that seeds might germinate even when they are too deep in the soil for seedlings to emerge. In turn this suggests that Trollius does not form a persistent soil seed bank and indeed this appears to be the case. In an experimental study comparing Primula veris (Cowslip) with T. europaeus, after 16 months burial, 85% of the Primula seeds, but only 8% of the Trollius seeds remained viable (Milberg 1994).
Competitive ability
T. europaeus is a poor competitor and in Finnish meadows has been known to suffer a prolonged delay in maturity, successful flowering and fruiting being curtailed for up to eight years. In the absence of competition, the species can fruit in its first season (Linkola 1936, quoted in Salisbury 1942, p. 54). The species is polycarpic and probably long-lived, continuing to fruit for a number of years after attaining maturity, so that the loss of between two and seven years' seed output in Finland may represent only a small percentage of the total production throughout the plant's life. However, the prolongation of the juvenile phase represents a greatly increased risk of mortality prior to any reproduction and this could be a significant factor determining the survival ability of the species in a particular plant community (Salisbury 1942). This delay in plant maturity is sometimes referred to as 'the demographic penalty', affecting the overall 'fitness' of a plant population (Silvertown & Lovett-Doust 1993, p. 158).
Plant and flower size plasticity
The flowers of T. europaeus at the Fermanagh lakeshore sites are much smaller, approximately a third the size of those the author has often observed elsewhere, including those in Teesdale, Co Durham (VC 66) (Clapham et al. 1978) and regularly found in the Swiss and Italian Alps and the Pyrenees at very much higher altitudes. This suggests a particular genetic clone with smaller flower occurs in Fermanagh, perhaps a response to a challenging waterside environment.
All plants allocate their limited photosynthetic energy and mineral nutrient resources under constraints and limits imposed by their local environment which ultimately acts upon the plant genotype, but is expressed in the readily observed and more easily measured variation of the population phenotype (Silvertown & Lovett-Doust (1993). Conflicting demands inevitably lead to trade-offs between different activities. Two classes of trade-off are virtually universal: (i.) a trade-off between reproduction and other activities which is manifest as 'the cost of reproduction', or in proportional terms as the 'reproductive effort' (RE); and, (ii.) a trade-off between the size and the number of offspring produced. For perennial plants, absolute allocation to reproduction usually increases with plant size. However, depending on the species under examination, the proportional reproductive allocation, ie the reproductive effort (RE), can either decrease, increase, or remain independent of plant size.
Comparative reproductive effort
A study of reproductive effort of populations of T. europaeus and Ranunculus acris (Meadow Buttercup), in subarctic Swedish Lapland compared the species at differing altitudes up to and above the tree-line (at 870 m). This showed that for both species plant size, measured in terms of 'mean plant biomass' (ie mean dry weight), was approximately two or three times larger below the tree line compared with above it (Hemborg & Karlsson 1998). For Trollius, plants at the high altitude sites showed no relationship between RE and size, while below the tree line, RE varied inversely with plant size, ie reproductive effort generally decreased as the Trollius plants became larger. This might be due to a limitation imposed by the number of flowering meristems the Swedish population could support, since all the plants in the study, irrespective of size only bore one flower per stem. Moreover, floral structures, eg flower size and ovule number, may be limited by low plasticity, features which are very likely both genetically and environmentally regulated (Schmid & Bazzaz 1992).
At low altitudes in Britain and Ireland, and in the French Alps, most plants of T. europaeus have two or three flowers per stem, the lateral flowers usually being smaller than the terminal. This fact alone would produce different size-effects on reproductive effort in comparison with this Swedish study (Hemborg & Karlsson 1998).
Toxins and herbal use
Globeflower contains protoanemonin, the same toxic principal present in other members of the family. Being a decidedly local plant, T. europaeus has never had the herbal medicinal reputation and uses of its more common and readily available relatives. The exception to this is perhaps found in Russia and parts of Sweden where the species is very prevalent (Grieve 1931).
Names
The genus name 'Trollius' is a Latinised version of the older Swiss-German name 'Trollblume', first coined by Gesner in the 16th century, which translates as 'rounded flower' (Gilbert-Carter 1964; Gledhill 1985). 'Trollblume' may well be a contraction of 'die rolle Blume', referring to the rolled in, or closed in, petals of the flower (Grigson 1987, p. 31). The Latin specific epithet is geographical and obvious.
There are 16 local English common names listed by Grigson (1987), of which various forms and spellings of 'Locken Gowan' are the most frequent. 'Gowan', 'Gowlan' and so on are derived from the Anglo-Saxon 'gold' meaning 'yellow', while 'Locken', 'Lockety', 'Locker', 'Lapper' and so on, refer to the locked or closed petaloid flower parts (Britten & Holland 1886; Grigson 1987). 'Locken Gowan' has also been sometimes used to refer to Caltha palustris (Marsh-marigold) and there is a fair degree of overlap with some of the other English common names between these two species. Other local names are more predictable not to say prosaic, eg 'Goldilocks', 'Golden Balls' and, of course, 'Globeflower'. The current author particularly likes the imagery generated by the name 'Bull-Jumpling', which hails from Kinross-shire: the 'bull' part is most probably a corruption of the Old English, 'boll', meaning, 'any globular body' (Prior 1879). The origin of 'Jumpling' we can only guess at. Another name mentioned by Gerard (1597) in his Herball, he being the first English writer to mention the whereabouts of the species in northern England, was 'Troll floures', or 'Troll flower'. Grigson (1987) is dismissive of this name, emphasising his belief that Trollius is not a flower in any way linked to the evil Nordic trolls. Prior (1879) disagrees though, comparing the name with the Scottish 'Witches Gowan'. According to him both these names were given on account of the plant's acrid poisonous properties.
Threats
In Fermanagh, reclamation of shore lines and, at least on Bilberry Island, grazing by goats. Potential shoreline building development could also prove deleterious.