Flora of the Canadian Arctic Archipelago
English: Moss campion,
French: Silène acaule,
Inuktitut: Airait/aupilattunguagujuq (Baffin Island), aupilattuguat, quaraq, anurisiutik (Nunavik).
Caryophyllaceae, Pink family.
Published in Enum. Stirp. Aūstriac. Vindob. 242. 1762.
Type: Selected by Talavera and Muños Garmendia, Anales Jard. Bot. Madrid 45: 445. 1989. Lectotype: LINN 583.61.
Synonymy. Cucubalus acaulis L., Sp. Pl. 415. 1753.
Xamilenis acaulis (L.) Tzvelev, Novosti Sist. Vyssh. Rast. 33: 94. 2001.
Silene acaulis (L.) Jacq. subsp. arctica Á. Löve and D. Löve, Univ. Colorado Stud., ser. biol., 17: 21. 1965.
S. acaulis (L.) Jacq. subsp. subacaulescens (F.N. Williams) C.L. Hitchc. and Maguire, Univ. Wash. Publ. Biol. 13: 22. 1947.
Vegetative morphology. Plants 2–5 cm high; perennial herbs; caespitose. Taproot present. Ground level or underground stems horizontal; rhizomatous, or stoloniferous; elongate, or compact; 0.8–2 mm wide. Horizontal stems at ground level, branching extensively to shape plant habit as cushions. Caudex present. Aerial stems erect and prostrate (plants grow from a taproot that develops numerous prostrate stems from which arise many compact erect branches). Leaves distributed along the stems; opposite; marcescent. Petioles absent. Leaf blade bases cuneate. Blades (3–)6–12 mm long, 1–1.3(–1.6) mm wide, spreading, lanceolate, flat, appearing single-veined. Blade adaxial surface dull, glabrous. Blade abaxial surface glabrous. Blade margins with non-glandular hairs (especially near the base); apices acute.
Reproductive morphology. Flowering stems two or more per plant; with leaves. Flowering stems hairy. Flowering stems pubescent. Flowering stem hairs simple; white or translucent (if applicable). Flowers solitary. Flowers medium-sized; unisexual, or bisexual. Sepals conventional; 5; fused; 4–6(–7.5) mm wide; purple, or green and purple; herbaceous; accrescent. Calyx tubular; 5-lobed; without sessile glands; glabrous. Calyx teeth equal or nearly so; 1.2–2 mm long. Petals conventional; free; longer than the calyx; 5; pink, or white (rarely); obovate; deeply cleft; 7–9 mm long. Stamens 10; stamen filaments glabrous. Anthers yellow; ellipsoid; 0.8–1 mm long. Ovary superior; carpels 3; syncarpous. Ovaries ovate; glabrous. Styles present; 3; free; 2.5–3.5 mm long. Stigmas per ovary 1. Placentation free central. Ovules per ovary 15–30. Fruit with calyx persisting; dry; a capsule; ovoid; yellowish, or black; 6–8(–11) mm long; 3–4 mm wide; surface appearing veinless; dehiscent; opening with teeth at the top of the capsule; teeth 6. Seeds several; 0.8–1 mm long; brown; surfaces verrucose.
Chromosome information. 2n = 24.
2n (2x) = 24. Flovik (1940, Svalbard); D. Löve (1942, northern Europe); Löve and Löve (1944b, Scandinavia; 1956, Iceland; 1966, northeastern USA); Löve and Löve, in Löve (1975a, northwestern USA); Löve and Löve (1982, central Canada, as 'arctica'); Sørensen and Westergaard, in Löve and Löve (1948, Greenland); Jørgensen et al. (1958, Greenland); Sokolovskaya and Strelkova (1960, northern Russia); Sorsa (1963b, Finland); Packer (1964, western Canada); Laane (1965, arctic Norway); Zhukova (1965a, eastern Chukotka); Mosquin and Hayley (1966, northern Canada); Hedberg (1967, northern Canada); Johnson and Packer (1968, northwestern Alaska); Engelskjøn and Schweitzer (1970, Bear Island); Engelskjøn and Knaben (1971, Norway); Kovanda (1978, USA, as 'acaulescens'); Dawe and Murray, in Löve (1979, Alaska); Dalgaard (1988, western Greenland). Several more southern counts.
Ploidy levels recorded 2x.
Ecology and habitat. Substrates: along streams, river terraces, tundra, slopes, ridges, cliffs; seepage slopes, dry, moderately well-drained areas; gravel, sand, silt, till; with low organic content; calcareous.
North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago widespread. Common. Arctic and alpine. Arctic islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry islands (Melville), Banks, Victoria, Somerset, King William, Southampton (Mill, Salisbury, Nottingham, and Prince Charles islands, Boothia and Melville peninsulas).
Northern hemisphere distribution. Circumpolar, or circumboreal (arctic-alpine, with a large Siberian gap). Northern Iceland, Northern Fennoscandian, KaninPechora, Svalbard Franz Joseph Land, Polar Ural Novaya Zemlya, YamalGydan, Taimyr Severnaya Zemlya, West Chukotka, South Chukotka, East Chukotka, West Alaska, North Alaska Yukon, Central Canada, Labrador Hudson Bay, Ellesmere Land Peary Land, West Greenland, East Greenland.
General notes. This is Wordsworth's Moss Campion of which he wrote:
"Upon it's native bed...
There, cleaving to the ground, it lies
With multitude of purple eyes,
Spangling a cushion green like moss."
The leaves and branches of S. acaulis form a compact cushion with an aerodynamic shape, which provides considerable protection from the drying winds of winter. Air flows over the cushion like the stream of air over an airplane wing, and snow easily covers the entire plant. In summer there is maximum exposed leaf surface for photosynthesis and minimum exposure to the elements (Burt 2000).
The numerous flowers are slightly fragrant and insect-pollinated. In addition to normal bisexual flowers and female flowers with rudimentary stamens (gynodioecy), bisexual flowers with reduced female organs are found (Jonsell 2001).
Abbott et al. (1995) contrasted the molecular diversity and derivations of populations of S. acaulis and Saxifraga oppositifolia from the High Arctic and more southern latitudes, based on a survey of allozyme diversity. They used populations of Silene acaulis from Svalbard, Norway, Iceland, and Scotland and found that populations from the High Arctic (Svalbard above 76°N) contained high levels of diversity and were genetically similar to populations from more southern locations. A restriction site analysis of chloroplast DNA (cpDNA) in S. acaulis revealed that all populations contained a single identical cpDNA haplotype, except one population from Norway, which also contained a second haplotype. Abbott et al. (1995) suggested that S. acaulis populations in the High Arctic have most likely been derived from immigrants that arrived from the south after the last glacial period, while the evidence suggested that Saxifraga oppositifolia may have northern stocks that survived the last glaciation in High Arctic refugia.
The 'exscapa' name has been used for the plants in the Amphi-Beringian area, but refers to a European endemic, according to Flora Europaea, and is probably inapplicable in the Arctic. The correct name for the arctic-alpine Pacific plants might be subsp. arctica, or subsp. subacaulescens for the pedunculate ones (Elven et al. 2003). As genetic evidence at this time does not justify recognition of several taxa, the subspecies that have been proposed are not applied here.
Illustrations. • Habitat: Dorset. Two cushions growing among the heather on dry tundra. Note more flowers on the side facing the sun. Nunavut, Baffin Island, Cape Dorset. 3 August, 2005. No voucher. • Habitat. Plants forming compact, hemispherical or flat cushions up to 50 cm in diameter. Iceland, Bolungarvík, Stigahliđ, alt. 400–590, 66°11'N, 23°22'W. June, 1995. Photograph by A. Brysting. • Underside of plant. Underside of plant with a major taproot and many tightly packed branches that make up the cushion. Nunavut, Baffin Island, Iqaluit. Aiken and Mallory 2002. No voucher. • Close-up of flowers. Flowers on the cushion with pink (or occasionally white) petals that are shallowly notched. Nunavut, Baffin Island, Iqaluit. 22 July, 1982. J.M. Gillett 18991. CAN. • Close-up of plant. Compact cushion plant with developing fruits, growing on gravel. Nunavut, Baffin Island, Iqaluit. 22 July, 1982. J.M. Gillett 18991. CAN. • Close-up of fruit. Unripe capsules longer than the fused calyx sepals. Norway, Espedal. June, 1976. With permission of the Botanical Museum, University of Oslo, Norway. Photograph by R. Borge. • Close-up of fruit. Longitudinal section of an unripe capsule showing free central placentation. Note the green axis with brown ovules attached. Norway, Espedal. June, 1976. With permission of the Botanical Museum, University of Oslo, Norway. Photograph by R. Borge. • Arctic Island Distribution.
This publication is available on the internet (posted May 2011) and on CD-ROM (published in 2007). These versions are identical in content, except that the errata page for CD-ROM is accessible on the main index page of the web version.
Recommended citation for the web-based version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. NRC Research Press, National Research Council of Canada, Ottawa. http://nature.ca/aaflora/data, accessed on DATE.
Recommended citation for the CD-ROM version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. [CD-ROM] NRC Research Press, National Research Council of Canada, Ottawa..