Flora of the Canadian Arctic Archipelago
English: Starwort mouse-ear chickweed,
French: Céraste à trois styles.
Caryophyllaceae, Pink family.
Published in Mem. Torrey Bot. Club. 5: 150. 1894.
Type: Selected by Jonsell and Jarvis, Nord. J. Bot. 14: 159. 1994. Lectotype: LINN 584.8.
Synonymy. Stellaria cerastoides L., Sp. Pl. 422. 1753.
Dichodon cerastoides (L.) Rchb., Icon. Fl. Germ. Helv. 5: f. 4915. 1841.
Cerastium trigynum Vill., Hist. Pl. Dauphin‚ 48. 1779.
Arenaria trigynum (Vill.) Shinners, Sida, i. 51. 1962.
Vegetative morphology. Plants 3–12 cm high (to 20 cm high in northern Europe); perennial herbs. Taproot present (slender). Ground level or underground stems horizontal; stoloniferous (rooting at the nodes); elongate, or compact; 0.7–1.5 mm wide. Horizontal stems at ground level, branching extensively to shape plant habit as mats (that are loose). Caudex absent. Aerial stems decumbent, or prostrate. Aerial stem trichomes spreading, or erect. Leaves present; distributed along the stems; opposite; marcescent. Petioles absent. Leaf blade bases cuneate, or attenuate. Leaves not grass-like. Blades 5–15 mm long, 1–4 mm wide, spreading or divaricate, elliptic or oblanceolate or linear, flat, appearing single-veined. Blade adaxial surface dull, glabrous. Blade abaxial surface glabrous. Blade margins glabrous; apices acute, or obtuse (more rarely).
Reproductive morphology. Flowering stems two or more per plant; with leaves. Flowering stems hairy. Flowering stems pubescent. Flowering stem hairs simple; white or translucent; glandular hairs present. Flowers in inflorescences (very rarely solitary). Inflorescences with flowers in a dichasium. Inflorescence main branches angle of divergence less than 30˚, or 30–60˚. Bract leaves with a distinct scarious margin; margins less than 0.3 mm. Flowers per inflorescence 1–4; medium-sized. Sepals conventional. Calyx base widely angled. Sepals 5; free; 1.5–2.5 mm long; 4–6 mm wide; green; herbaceous and scarious (the margins). Calyx hairy. Calyx hairs pubescent; glandular; white or translucent. Petals conventional; free; longer than the calyx; 5; white (more or less translucent); obovate, or spatulate (narrowly so); notched (the notch approximately 0.2x the length of the petal); 5–9 mm long; 2–3.5 mm wide. Stamens 10; stamen filaments glabrous. Anthers yellow; ellipsoid; 0.6–0.9 mm long. Ovary superior; carpels 3 (usually), or 4 (rarely); syncarpous. Ovaries oblong; glabrous. Styles present; 3 (usually, 4 rarely); free; 2–3 mm long. Stigmas per ovary 1. Placentation free central. Ovules per ovary 20–50. Fruit with calyx persisting; dry; a capsule; oblong, or urceolate (slightly); straw-coloured; 5–10 mm long; 1.5–3.5 mm wide; surface appearing veinless; mouth straight; dehiscent; opening with teeth at the top of the capsule; teeth 6 (usually, or 8 rarely). Seeds numerous; 0.8–1.2 mm long; yellowish (pale brown); surfaces verrucose (stelliform when viewed from above).
Chromosome information. 2n = 38 (34, 36, and 40).
2n = 34. Böcher and Larsen (1950, Greenland);
2n = 36. Mattick, in Tischler (1950, Austria);
2n = 38. Sørensen and Westergaard, in Löve and Löve (1948, Greenland); Böcher and Larsen (1950, Greenland); Löve and Löve (1956, Iceland); Jørgensen et al. (1958, Greenland); Dalgaard (1988, western Greenland). Several more southern counts (e.g., Favarger and Söllner 1949, Favarger 1969).
2n (2x) = 40. Böcher (1938); Sörensen and Westergaard, in Löve and Löve (1948). Supposed basic chromosome number of family 9.
Ploidy levels recorded 4x.
Ecology and habitat. Substrates: wet meadows, snow patches, along streams, lakeshores; imperfectly drained moist areas, seepage slopes; gravel, sand, silt; with low organic content; acidic, or calcareous, or non-calcareous.
North American distribution. Nunavut Islands, Labrador, Newfoundland. Range in the Canadian Arctic Archipelago limited. Rare. Low Arctic. Arctic islands: Baffin.
Northern hemisphere distribution. Amphi-Atlantic. Northern Iceland, Northern Fennoscandian, KaninPechora, Svalbard Franz Joseph Land, Polar Ural Novaya Zemlya, Labrador Hudson Bay, West Greenland, East Greenland.
General notes. Cerastium cerastoides is gynodioecious (displaying female plants as well as hermaphrodites), and slightly protandrous (Warming 1920). The seeds develop fairly regularly even when flowering is late. Local dispersal takes place by rooting shoot fragments (Jonsell 2001a).
Illustrations. • Close-up of plant. Plant growing in wet meadow. Photograph by R. Borge. With permission of the Botanical Museum, University of Oslo, Norway. • Close-up of plant. Plant growing in morainic material consisting mainly of dark phyllite. Norway, Hordaland, Ulvik, Omnsbreen, 60°39'N, 7°30'E. August, 1973. Photograph by R. Elven. • Close-up of inflorescence. Inflorescence a dichasium. Plant entirely glabrous except for a line of fine glandular hairs at one side of the flowering stems. Norway, Hedmark, Sjusjøen. July 1971. Photograph by R. Borge. With permission of the Botanical Museum, University of Oslo, Norway. • Close-up of flower. Petals longer than the calyx and more or less translucent. Norway, Hedmark, Sjusjøen. Photograph by R. Borge. July, 1971. With permission of the Botanical Museum, University of Oslo, Norway. • Close-up of flower. Close-up of flower with petals that are longer than the calyx, 2-lobed (the notch 1/3 the length of the petal), 10 stamens and usually 3 styles. Photograph by R. Borge. 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..