Sagina L.
Pearlwort.
Sp. Pl. 128. 1753.
Spergella Rchb.
Vegetative morphology. Plants 1–10 cm high; vegetatively proliferating by bulbils or fragmentation, or not vegetatively proliferating by bulbils or fragmentation. Taproot present. Caudex absent. Ground-level or under-ground stems horizontal, or not developed horizontally or vertically; stoloniferous; elongate, or compact; 0.5–1.2 mm wide. Aerial stems erect, or decumbent; glabrous, or sparsely hairy; stem hairs spreading, or erect. Leaves distributed along the stems, or basal in a rosette. Leaf blade bases cuneate. Blades (2–)4–12(–25) mm long; 0.3–1.2 mm wide. Blades spreading; herbaceous; linear; flat, or folded; with inconspicuous veins. Blades adaxial surface dull; glabrous. Blades abaxial surface glabrous. Blade margins glabrous. Leaf apices acuminate, or acute, or mucronate.
Reproductive morphology. Plants bisexual, or bisexual and agamospermic. Flowering stems glabrous, or hairy. Flowering stem hairs pubescent. Flowering stems glandular hairs present. Flowering stem hairs white or translucent. Flowers solitary, or in inflorescences. Inflorescence a dichasium. Flowers per inflorescence 1–3; small, less than 5 mm in diameter or length, or medium-sized, 5–15 mm in diameter or length. Calyx sepals 5, or 4; free; 1.4–3.5(–4) mm long. Calyx green, or green and purple; herbaceous, or herbaceous and scarious; glabrous, or hairy. Calyx hairs glandular; white or translucent (if applicable). Petals same length as the calyx, or longer than the calyx; 4, or 5; white; obovate, or lanceolate; unlobed; 1.4–6 mm long. Stamens 10, or 8–10. Anthers yellow; ellipsoid, or ovoid; 0.2–1 mm long. Carpels 4, or 5. Ovaries ovate. Styles 4, or 5; 0.4–3.5 mm long. Ovules 8–25. Fruit ovoid; teeth 5 (usually, or 4). Fruit 2–4.5 mm long; 1.5–3 mm wide; golden brown, or straw coloured. Seeds (0.4–)0.5–1 mm long; brown; with surfaces verrucose.
Chromosome information. 2n = 52, 56, 70–74, 77.
Distribution. Northern hemisphere distribution: circumpolar, or circumboreal; Greenland, Canada, United States, Eurasia.
Illustrations. • Sagina cespitosa. Plant forming small, rather compact, hemispherical tufts, 1–9 cm in diameter. Norway. Photo by R. Elven. • Sagina nivalis. Plant in fruit, growing in disturbed ground at the edge of a road; flowering stems radiating from the base of a central rosette. Nunavut, Rankin Inlet, near the graveyard, 62°48'N, 92°06'W. Aiken and Brysting 01–046. CAN. • Sagina nodosa subsp. borealis. Flowering plant growing in dry, sun baked dolomite gravel. Manitoba, Churchill, Beech Bay, in the tidal estuary of the Churchill River, south of the Port, 58°44.30'N, 94°08.06'W. Aiken and Brysting 01–032. CAN.
Cite this publication as: ‘A.K. Brysting, P.J. Scott, and S.G. Aiken 2001 onwards. Caryophyllaceae of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993, 1995, 2000) , and Aiken, Dallwitz et al. (1999) should also be cited (see References).
