Flora of the Canadian Arctic Archipelago

DELTA Home

S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, L.J. Gillespie, A.K. Brysting, H. Solstad, and J.G. Harris

Cerastium L.

English: Mouse-ear chickweed, starwort.

Caryophyllaceae, Pink family.

Published in Sp. Pl. 437. 1753.

Vegetative morphology. Plants 1.5–30(–45) cm high; perennial herbs; sometimes vegetatively proliferating by bulbils on stems or leaves, or never vegetatively proliferating by bulbils on stems or leaves, in inflorescences, from gemmiphores and gemmae, or by fragmentation. Taproot present (slender). Ground level or underground stems horizontal, or absent; rhizomatous; elongate, or compact; 0.5–1.5 mm wide. Caudex absent. Aerial stems erect, or ascending, or decumbent, or prostrate. Aerial stem trichomes spreading, or erect, or retrorse. Leaves distributed along the stems, or mainly basal; opposite; marcescent. Petioles absent. Leaf blade bases cuneate, or attenuate. Blades 4–21(–30) mm long, 1–7.5 mm wide, spreading or divaricate, linear or oblong or elliptic or lanceolate or ovate or oblanceolate or obovate or spatulate, flat, appearing single-veined. Blade adaxial surface dull or shiny, glabrous or hairy, hairs pilose or villous or short-silky, hairs simple or glandular and simple, hairs sparse or moderately dense or dense, hairs white, or translucent. Blade abaxial surface glabrous or hairy, hairs pilose or villous or strigose, hairs sparse or moderately dense or very dense, hairs white. Blade margins glabrous or with non-glandular hairs and with glandular hairs; apices acute, or obtuse.

Reproductive morphology. Plants bisexual, or bisexual and agamospermic. Flowering stems with leaves. Flowering stems hairy. Flowering stems pubescent, or pilose, or villous. Flowering stem hairs simple; white or translucent; glandular hairs present. Flowers solitary, or in inflorescences. Inflorescences with flowers in a dichasium. Inflorescence main branches angle of divergence less than 30˚, or 30–60˚, or 60–90˚. Bract leaves 2–9 mm long; 0.6–6 mm wide; with a distinct scarious margin, or without a distinct scarious margin; margins less than 0.3 mm, or margins 0.3–0.8 mm. Flowers per inflorescence 1–10(–20); small, or medium-sized. Sepals conventional. Calyx base narrowly angled, or widely angled, or rounded. Sepals 5; free; (1–)1.2–3.1 mm long; (2–)3.5–9 mm wide; green, or green and purple; herbaceous and scarious. Calyx hairy. Calyx hairs pubescent, or pilose, or villous; glandular, or glandular and non-glandular; white or translucent. Petals conventional; free; longer than the calyx; 5; white; without contrasting markings; obtriangular (usually), or obovate, or spatulate; notched; 5–10(–13) mm long; 2–7 mm wide. Stamens 10; stamen filaments glabrous. Anthers yellow; ellipsoid; 0.4–0.9 mm long. Ovary superior; carpels 5 (usually), or 3, or 4; syncarpous. Ovaries oblong; glabrous. Styles present; 5 (usually), or 3; free; 2–3.5 mm long. Stigmas per ovary 1. Placentation free central. Ovules per ovary 20–50. Fruit with calyx persisting; dry; a capsule; elongate-cylindrical, or oblong, or urceolate; straw-coloured; 5–16 mm long; 1.5–5 mm wide; surface appearing veinless; mouth straight, or curved; dehiscent; opening with teeth at the top of the capsule; teeth 10 (usually), or 6 (8 in species not in the Canadian Arctic Archipelago). Seeds numerous; 0.7–1.3 mm long; brown (reddish), or yellowish; surfaces verrucose, tuberculate.

Chromosome information. 2n = 38, 72, and 108.

Supposed basic chromosome number of family 9.

Illustrations. • Cerastium alpinum. Calyx base narrowly angled with petals that are longer than the sepals, 2-lobed (the notch 0.2–0.25x the length of the petal). Note the small pedicel bract leaves. Nunavut, Rankin Inlet, 62°48'N, 92°06'W. Aiken and Brysting 01–052. CAN. • Cerastium arcticum. Isolated plant with densely cespitose growth, growing in dry, calcareous gravel at a graveyard near the road to the airport. Nunavut, Salliq (Coral Harbour), 64°08'13"N, 83°09'53"W. Aiken and Brysting 01–080. CAN. Scale bar in cm. • Cerastium arvense. Inflorescence a dichasium with 2 central flowers gone to seed and lateral flowers. Note the small bract leaves with a distinct scarious margin. Photograph by R. Borge. With permission of the Botanical Museum, University of Oslo, Norway. • Cerastium beeringianum. Inflorescence a dichasium. Nunavut, Southampton Island, Salliq (Coral Harbour), coastline east of the Northern Store, 64°08'13"N, 83°09'53"W. Aiken and Brysting 01–075. CAN. • Cerastium cerastoides. Inflorescence a dichasium. Plant 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. • Cerastium regelii. Leaves ovate or obovate, glabrous (sometimes ciliated at the margins), somewhat fleshy and shiny. Plants in the High Arctic rarely flower. Nunavut, Ellesmere Island, Scoresby Bay, 79°53'N, 71°33'W. Aiken 98–036. CAN. Photograph by Mollie MacCormac.


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.

.

Contents