Flora of the Canadian Arctic Archipelago
English: Regel's mouse-ear chickweed.
Caryophyllaceae, Pink family.
Published in Skr. Norske Vidensk.-Akad. Christiania, Math.-Naturvidensk. Kl. 1908, 8: 10. 1910.
Type: Canada, King William Island, 31.07.1904, leg. Lindström, selected by Jonsell, Nord. J. Bot. 16: 6. 1996. Lectotype: O.
Synonymy. Cerastium regelii subsp. caespitosum (Malmgr.) Tolm., Fl. Arct. URSS 6: 41. 1971.
Cerastium alpinum L. var. (gamma) caespitosum Malmgren (1862), 'Spetsb. Fanerogamfl.' 242. 1862.
?Cerastium. jenisejense Hultén, Svensk Bot. Tidskr. 50: 473.1956.
Cerastium gorodkovianum Schischkin, In Komarov, Fl. URSS, vi. 547. 883. 1936.
Vegetative morphology. Plants 2–6(–8) cm high; perennial herbs; sometimes vegetatively proliferating by bulbils on stems or leaves (terminal buds, often not flowering). Taproot present (slender). Ground level or underground stems horizontal, or absent (usually); stoloniferous, or rhizomatous; elongate; 0.5–1.2 mm wide. Horizontal stems at ground level, branching extensively to shape plant habit as mats (compact), or cushions. Caudex absent. Aerial stems decumbent. Aerial stem trichomes spreading, or erect. Leaves mainly basal, or distributed along the stems; opposite; distinctly distichous; marcescent. Petioles absent. Leaf blade bases cuneate, or attenuate. Blades 4–7(–9) mm long, (1.5–)3–4(–6) mm wide, spreading, elliptic or ovate or obovate, flat, appearing single-veined. Blade adaxial surface shiny, glabrous. Blade abaxial surface glabrous. Blade margins glabrous or with non-glandular hairs; apices obtuse, or acute.
Reproductive morphology. Plants bisexual and agamospermic (producing bulbils in the shoot apices early in the season, on flowering stems later in the season). Flowering stems two or more per plant; with leaves. Flowering stems hairy. Flowering stems pilose, or villous. Flowering stem hairs simple; white or translucent; glandular hairs present. Flowers solitary (usually), or in inflorescences. Inflorescences with flowers in a dichasium. Inflorescence main branches angle of divergence less than 30˚, or 30–60˚. Bract leaves 3–4 mm long; 1.5–3 mm wide; with a distinct scarious margin; margins less than 0.3 mm. Flowers per inflorescence (1–)2–4(–5); medium-sized. Sepals conventional. Calyx base rounded. Sepals 5; free; 1.8–2.5 mm long; 3.5–6.5 mm wide; green, or purple (at least towards the margins); herbaceous and scarious (0.5–0.7 mm broad, scarious margins). Calyx hairy. Calyx hairs pilose; glandular and non-glandular; white or translucent. Petals conventional; free; longer than the calyx; 5; white; obtriangular; notched; 6.5–7.5(–11) mm long; 4–5 mm wide. Stamens 10; stamen filaments glabrous. Anthers yellow; ellipsoid; 0.6–0.8 mm long. Ovary superior; carpels 5; syncarpous. Ovaries oblong; glabrous. Styles 5; free; 2–3.5 mm long. Stigmas per ovary 1. Placentation free central. Ovules per ovary 20–40. Fruit with calyx persisting; dry; a capsule; oblong; straw-coloured; 7–8 mm long; 1.8–2.5 mm wide; surface appearing veinless; mouth straight; dehiscent; opening with teeth at the top of the capsule; teeth 10. Seeds numerous; 0.8–1 mm long; brown; surfaces verrucose.
Chromosome information. 2n = 72.
2n (4x) = 72. Flovik (1940, Svalbard, as 'regelii'); Holmen (1952, Greenland, as 'regelii'); Zhukova (1966, northeastern Asia, as 'regelii'; 1980, southern Chukotka, as 'jenisejense'; 1982, Chukotka, as 'jenisejense'); Hedberg (1967, northern Canada, 2n = about 72 as 'regelii'); Sokolovskaya (1970, northern Russia, 'jenisejense'); Zhukova and Petrovsky (1972, Wrangel Island, as 'jenisejense'); Zhukova et al. (1973, northern and northeastern Asia, as 'jenisejense'); Packer and McPherson (1974, northern Alaska, as 'jenisejense'); Böcher (1977, 2n = 82–86, a hybrid?); Engelskjøn (1979, Svalbard, as 'regelii'). Supposed basic chromosome number of family 9.
Ploidy levels recorded 8x.
Ecology and habitat. Substrates: hummocks, snow patches, around the margins of ponds, depressions of low-centre polygons, along streams, river terraces, lakeshores (sandy beaches), tundra; imperfectly drained moist areas, seepage slopes; sand, silt, clay, moss; with low organic content, with high organic content, peat; acidic, or calcareous.
North American distribution. Alaska, Yukon (?), Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut. Range in the Canadian Arctic Archipelago widespread. Common. High Arctic. Arctic islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry islands, Cornwallis, Banks, Victoria, Prince of Wales, Somerset, King William (Stefansson and Ellef Ringnes Islands).
Northern hemisphere distribution. Circumpolar. Northern Fennoscandian, KaninPechora, Svalbard Franz Joseph Land, Polar Ural Novaya Zemlya, YamalGydan, Taimyr Severnaya Zemlya, AnabarOlenyok, Kharaulakh, YanaKolyma, West Chukotka, Wrangel Island, East Chukotka, West Alaska, North Alaska Yukon, Central Canada, Labrador Hudson Bay, Ellesmere Land Peary Land, East Greenland.
General notes. Mature seeds have never been found in northern arctic populations, probably because the plants flower late. In these areas, most propagation is by bulbils borne in the shoot apices. C. regelii has been found to be conspecific with the boreoarctic C. jenisejense Hultén, a plant without bulbils and which flowers early in the season (Heide et al. 1990). These authors considered C. jenisejense a morpho-type of C. regelii, induced by different temperature and daylight regimes at lower latitudes. In the Flora of North America treatment, Morton (2005) recognises C. gorodkovianum Schischkin as a separate species, similar to C. regelii but more creeping in its habit. He notes that the two taxa simply may be growth forms of the same species and includes C. jenisense as a synonym of C. gorodkovianum. Here, both C. gorodkovianum and C. jenisense are included as synonyms of C. regelii, following Heide et al. (1990).
The amphi-Atlantic part of the species has often been considered as a separate subspecies, subsp. caespitosum (Malmgren) Tolm.
Cerastium regelii differs from the other Cerastium species in having more contracted growth, round glabrous leaves, and by the production of bulbils in the shoot apices. The hybrid C. arcticum ×regelii differs from C. regelii in having elongated and pubescent leaves and flowering profusely from early in the season (Elven and Elvebakk 1996).
Illustrations. • Habitat. Compact plant growing in drier tundra near a seepage area. Nunavut, Resolute Bay, beside hamlet, 74░68'N, 94░48'W. Aiken and Brysting 01–122. CAN. Scale bar in cm. • Close-up of plant. Leaves ovate or obovate, glabrous (sometimes ciliated at the margins), somewhat fleshy and shiny. Plants in the High Arctic rarely flower. Ellesmere Island, Nunavut, Scoresby Bay, 79░53'N, 71░33'W. Aiken 98–036. CAN. Photograph by Mollie MacCormac. • Close-up of flowers. Flowers usually solitary with a rounded calyx base and five notched petals. Plants growing in seepage area of frost boil tundra in a thermal oasis. Nunavut, Ellesmere Island, Scoresby Bay, 79░53'N, 71░33'W. Aiken 98–036. CAN. Photograph by Mollie MacCormac. • Drawing of plant. Drawing by Mrs. S. Bergh and Mrs. L. Barstad based on a collection from Svalbard, Dickson Land, Dickson Bay, Hugins dal, sletta vd sj°en [plain by sea]. 11 August, 1924. J. Lid (confirm. E. HultÚn 1955). O 203774. With permission of the Botanical Museum, University of Oslo, Norway. • Drawing of plant. Drawing by Mrs. S. Bergh and Mrs. L. Barstad based on a collection from Bear Island, Kapp Levin. 5 September, 1924. J. Lid (as C. regelii, det. C. arcticum x regelii A. Tolmatchew 1929, det. C. regelii E. HultÚn 1955). O 207712. With permission of the Botanical Museum, University of Oslo, Norway. • 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..