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Antennaria dioica (L.) Gaertn., Mountain Everlasting

Account Summary

Native, occasional. Eurasian boreo-temperate.

1882; Stewart, S.A.; Carrick Td.

April to December.

Growth form and preferred habitats

A rosette-forming perennial with surface creeping, leafy stolons that root at the nodes, and simple, entire, wintergreen leaves, ± folded along their length, dark green above and backed with a conspicuous white woolly tomentum of hairs, A. dioica is unmistakably identifiable throughout the year. A low-growing, mat-forming species, it has male and female flowers on different plants (the term 'dioecious', which is reflected in the species epithet, comes from the Greek meaning 'two households'). Each head is composed of many tiny flowers that are not bisexual, ie possessing both male and female organs, but rather they are functionally either male or female. Male heads are most easily determined as the tips of the anthers protrude a little and they are much more visible than the stigmas in female heads.

Essentially, A. dioica is a plant of short stature, open vegetation maintained by light to moderate livestock grazing of rocky hillside grassland, often on sunny, relatively warm, dry or well-drained, shallow, moderately acidified soils. These conditions are most commonly met over limestone, but can also occur under much more acidic, siliceous, moist, but still relatively free-draining conditions on heathy grassland dominated by Calluna vulgaris (Heather) and other ericaceous sub-shrubs. Mountain Everlasting also occurs occasionally on rock ledges of cliffs and in old quarries and, more rarely, on limestone or base-rich screes, or stony or gravelly pastures. At the coast, it can also occur on sand-dunes.

In grasslands, A. dioica appears where the grazing and burning management regime sufficiently reduces the dominance of the woody element of heathy vegetation, and particularly where this disturbance more or less eliminates gorse (Ulex europaeus), allowing a somewhat richer admixture of herbaceous plants to co-exist. It cannot survive very heavy grazing or trampling, but, on the other hand, it cannot compete with taller, more vigorous plants if the vegetation is under-grazed (Sinker et al. 1985; Bradshaw 2023). The typical vegetation it occupies belongs to the Antennario-Calllunetum Tx. 1937 (White & Doyle 1982, p. 343 and a whole range of eight British heathland communities (H10, H13 to H17 and H19 & H20) (Rodwell et al. 1991b, 2, p. 471-575).

The established strategy of A. dioica is categorised as SR/CSR, meaning it is considered intermediate between a Stress-tolerant Ruderal and a more balanced mix of all three plant strategies, Competitor, Stress-tolerator and Ruderal (Grime et al. 1988, 2007).

Flowering reproduction

A. dioica belongs to a species complex in which apomixis does occur (and especially so in arctic and alpine environments). However, most populations examined in B & I consist of intermingled male and female plants, which suggests normal sexual reproduction takes place here. The species generally flowers between June and July in NW Europe, including within its B & I range (although it can begin in May in W Ireland) (K.J. Walker, in: Stroh et al. 2019). The flowerheads are shortly stalked, two-eight together forming a closely-packed terminal corymb. The male flowerheads are only c 6 mm in diameter, while the female heads are about twice as large, c 12 mm in diameter. The flowers composing the flowerheads are either pink or white in colour, but this does not reflect their sex: male heads can be of either pink or white, while the females are usually rose-pink, but the colour does vary and they can be almost red (Clapham et al. 1987; Nelson & Walsh 1991). The flowerheads are rayless, but are surrounded by ± spreading pink or white bracts. The slender, erect, white woolly-coated flowering shoots are 5-20 cm tall and bear upward-pointing linear leaves (Clapham et al. 1987; Perring & Walters 1989).

The flowers attract a wide variety of insect pollinators, including butterflies, moths, bees, flies and beetles (K.J. Walker, in: Stroh et al. 2019). The achene fruits measure 1 mm in length and are furnished with a white pappus of hairs that aids their wind dispersal (Clapham et al. 1987). The soil seed bank survey of NW Europe listed only a few estimates of A. dioica seed (achene) survival and all of them regarded it as transient (ie persisting less than one year) (Thompson et al. 1997).

Fermanagh occurrence

'Cat's Foot' or 'Mountain Everlasting', to give two of the English common names, is a familiar, frequently found species of Fermanagh's drier, stony heaths and upland pastures and it has been recorded in a total of 45 tetrads, 8.5% of those in the VC.

Antennaria dioica has declined in Fermanagh during the last 40 years or so, since there are eleven tetrads with only pre-1976 records. This can undoubtedly be attributed to the ploughing, manuring and re-seeding of lowland calcareous pastures and heaths in the name of 'agricultural grassland improvements'.

Irish occurrence

In Ireland, A. dioica is largely a plant of the midland and western limestone districts, descending with other so-called 'mountain species' close to sea-level along the W coast, stretching from W Donegal (H35) to S Kerry (H1). It is especially frequent and locally abundant in the Burren, Co Clare (H9) and, to a lesser extent, in parts of Connemara (H15-H17). It is widespread but local elsewhere in this part of the country (Webb & Scannell 1983).

In Fermanagh (H33), A. dioica descends to the shores of Lower Lough Erne, appearing for instance on limestone pavement at Gubbaroe Point.

British occurrence

Populations have suffered declines and A. dioica is now rather rare in lowland areas of England and Wales on chalk and limestone grasslands including dunes and maritime heaths. However, it still remains widespread in upland areas from the Brecon Beacons (recently renamed in Welsh, 'Bannau Brycheiniog'), and the Peak District northwards, and it is especially frequent in NW Scotland and in the Scottish Highlands and islands (K.J. Walker, in: Stroh et al. 2019; Bradshaw 2023).

European and world occurrence

A. dioica belongs to the Boreo-temperate phytogeographical element and its distribution stretches across most of Europe except the far south. It is absent from most of the Mediterranean, except the northern half of Italy and part of the Adriatic Balkans. The distribution continues north and eastwards to Siberia and to eastern Asia, reaching China and Japan. It also reaches N America, but here it is confined to the W Aleutian Islands, Alaska (Hultén & Fries 1986, Map 1783; K.J. Walker, in: Stroh et al. 2019). While A. dioica grows on soils derived from both limestone and siliceous rocks in Ireland, and appears on limestone in several areas in Britain, in Europe it is widely regarded as a calcifuge species (ie lime-avoiding).

Names

The genus name 'Antennaria' is said to be associated or derived from the Latin 'antenna', 'a sail-yard', the pappus of hairs attached to the achene resembling the antennae or 'feelers' of an insect (Johnson & Smith 1946; Gilbert-Carter 1964).

Grigson (1955, 1987) lists just three English common names, 'Cat's-foot', 'Cat's-paw' and 'Moor Everlasting'. The more frequent names that he ignores are closely related, namely 'Mountain Everlasting' and 'Cat's-ear' (Britten & Holland 1886). The names reflect the white wooliness of the leaves and stems and the fact that the plant can be dried and used indefinitely for ornament.

Threats

Atmospheric pollution leading to acidification and eutrophication of grassland and heath habitats shifts the competitive balance towards more vigorous species that can oust A. dioica.

References

White, J. and Doyle, G. (1982); Rodwell, J.S. et al.(b) (1991); Hultén & Fries 1986; Clapham et al. 1987; Perring & Walters 1989; Nelson & Walsh 1991; Thompson et al. 1997; Stroh et al. 2019; Webb & Scannell 1983; Grime et al. 1988, 2007; Sinker et al. 1985; Bradshaw 2023; Grigson (1955, 1987); Johnson & Smith 1946; Gilbert-Carter 1964; Britten & Holland 1886.