Cerastium regelii Ostenf.
Regel's Mouse-ear Chickweed.
Caryophyllaceae, pink family.
Skr. Norske Vidensk.-Akad. Christiania, Math.-Naturvidensk. Kl. 1908, 8: 10. 1910.
Type: Canada, King William Land, 31.07.1904, leg. Lindström (O) lectotype, selected by Jonsell, Nord. J. Bot. 16: 6. 1996.
Cerastium alpinum L. var. (gamma) caespitosum
Malmgren
Cerastium edmondstonii (Edmondston) Murb. and Ostenf. var.
cespitosum (Malmgren) Andersson and Hesselmann
Cerastium
regelii Ostenf. subsp. caespitosum (Malmgren) Tolm.
Cerastium
alpinum L. f. pulvinatum Simmons
Cerastium gorodkovianum
Schischkin
Cerastium jenisejense Hultén
Two subspecies in Kartesz (1994).
Vegetative morphology. Plants perennial herbs; 2–6(–8) cm high; forming cushions or compact mats; vegetatively proliferating by bulbils or fragmentation (terminal buds, often not flowering). Taproot present (slender). Caudex absent. Ground-level or under-ground stems not developed horizontally or vertically, or horizontal; stoloniferous, or rhizomatous; elongate; 0.5–1.2 mm wide. Aerial stems decumbent; glabrous, or sparsely hairy; stem hairs spreading, or erect. Leaves in a basal tuft, or distributed along the stems; opposite; marcescent. Petioles absent. Leaf blade bases cuneate, or attenuate. Blades 4–7(–9) mm long; (1.5–)3–4(–6) mm wide. Blades spreading; somewhat fleshy; elliptic, or ovate, or obovate; flat; appearing single-veined. Blades adaxial surface shiny; glabrous. Blades abaxial surface glabrous. Blade margins glabrous, or with non-glandular hairs. Leaf apices obtuse, or acute.
Reproductive morphology. Plants bisexual and agamospermic (producing bulbils in the shoot apices early in the season, flowering stems later in the season). Flowering stems with leaves; hairy. Flowering stem hairs pilose, or villous; simple. Flowering stems glandular hairs present (in the upper parts, glabrous below). Flowering stem hairs white or translucent. Flowers solitary (usually), or in inflorescences. Inflorescence a dichasium; main branches angle of divergence less than 30 degrees, or 30–60 degrees. Pedicels 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 1–4(–5); medium-sized, 5–15 mm in diameter or length. Calyx base rounded. Calyx sepals 5; free; 3.5–6.5 mm long; 1.8–2.5 mm wide. Calyx green, or purple (at least towards the margins); herbaceous and scarious (0.5–0.7 mm broad, scarious margins); hairy; pilose. Calyx hairs glandular and non-glandular; white or translucent. Petals free; longer than the calyx; 5; white; obtriangular; shallowly lobed; 6.5–7.5(–11) mm long; 4–5 mm wide. Stamens 10; filaments glabrous. Anthers yellow; ellipsoid; 0.6–0.8 mm long. Gynoecia superior. Carpels syncarpous; 5. Ovaries oblong; glabrous. Styles 5; free; 2–3.5 mm long. Stigmas per style 1. Placentation free central. Ovules 20–40. Fruit with calyx persisting; dry; a capsule; oblong; mouth straight; dehiscent; opening with teeth at the top of the capsule; teeth 10. Fruit 7–8 mm long; 1.8–2.5 mm wide; straw coloured; surface appearing veinless. Seeds numerous; 0.8–1 mm long; brown; with surfaces verrucose.
Chromosome information. 2n = 72. 72 (4x). - Flovik (1940 Svalbard, as 'regelii'); Holmen (1952 Greenland, as 'regelii'); Zhukova (1966 north eastern Asia, as 'regelii', 1980 southern Chukotka, as 'jenisejense', 1982 Chukotka, as 'jenisejense'); Hedberg (1967 northern Canada, 2n = c.72 as 'regelii'); Sokolovskaya (1970, northern Russia, 'jenisejense'); Zhukova and Petrovsky (1972, Wrangel Island, as 'jenisejense'); Zhukova et al. (1973 northern andnortheatern 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.
Distribution. Northern hemisphere distribution: circumpolar; Greenland, Canada, United States, Eurasia. Alaska, Northwest Territories Islands, Continental Northwest Territories, Nunavut Islands, Continental Nunavut, Northern Québec. High arctic. Range in the Canadian Arctic Archipelago widespread. Common. Arctic Islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry Islands, Cornwallis, Banks, Victoria, Prince of Wales, Somerset, King William (Stefansson and Ellef Ringnes Islands).
Ecology and habitat. Substrates: hummocks, snow patches, around the margins of ponds, depressions of low centre polygons, along streams, river terraces, lake shores (sandy beaches), tundra; imperfectly drained moist areas, or on seepage slopes; acidic, or calcareous; sand, silt, clay, moss; with low organic content, or with high organic content, or peat.
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). Heide et al. (1990) considered C.
jenisejense a morpho-type of C. regelii, induced by different
temperature and day-light regimes at lower latitudes. In the developing Flora of
North America, Morton (personal communication) 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 x regelii
differs from C. regelii in having elongated and pubescent leaves and
flowering profusely from early in the season (Elven and Elvebakk 1996).
Illustrations. • Plant 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. • 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 plant. Leaves ovate or obovate, glabrous (sometimes ciliated at the margins), somewhat fleshy and shiny; marcescent and bleached leaves persist on the stems for several years; plants in the high Arctic rarely flower and the main way of propogation is by bulbils in the shoot apices. Nunavut, Resolute Bay, beside hamlet, 74°68'N, 94°48'W. Aiken and Brysting 01–122. CAN. • Close-up of flowers. Flowers usually solitary; calyx base rounded. Plants growing in seepage area of frost boil tundra. Ellesmere Island, Nunavut, 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 sjøen [plain by sea]. 11 Aug. 1924. J. Lid (confirm. E. Hultén 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 Sep. 1924. J. Lid (as C. regelii, det. C. arcticum x regelii A. Tolmachev 1929, det. C. regelii E. Hultén 1955). O 207712. With permission of the Botanical Museum, University of Oslo, Norway. • Distribution map.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 1999 onwards. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
