Plants perennial, delicate, forming small to large tangled mats or straggling through grass, from slender rhizomes. Stems diffusely branched, 4-angled, 3-30 cm, gla-brous. Leaves sessile or subsessile; blade with midrib obscure, broadly elliptic-lanceolate to linear-lanceolate, widest at or above middle, 0.2-0.8(-1.5) cm × to 2 mm, ± succulent, base cuneate, margins entire, apex acute to acuminate, glabrous; leaf blades in terminal buds sometimes become fleshy and form gemmae. Inflorescences with flowers usually solitary, terminal and in axils of distal leaves forming open, diffuse cymes; bracts foliaceous, 1-10 mm; 1 or 2 pairs of bracteoles sometimes present, 1-3 mm, herbaceous or with narrow membranous margins. Pedicels erect or sharply angled at base, becoming sharply curved at apex, 3-40 mm, glabrous. Flowers 5-8 mm; sepals 5, 3-veined, narrowly triangular-lanceolate, 3-3.5(-4) mm, margins straight, narrow, scarious, apex acute, glabrous or rarely margins pubescent; petals 5, 2.5-5 mm, equaling to slightly longer than sepals; stamens 5 or 10; styles 3, ascending, curved at tip, ca. 2 mm. Capsules straw colored, conic to ellipsoid, 4-5 mm, longer than sepals, apex obtuse, opening by 6 valves; carpophore absent. Seeds reddish brown, reniform to round, 0.7-1 mm diam., rugose. 2n = 26. Flowering early summer. Marshes, streams, cold, wet, grassy places; 0-3000 m; Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., P.E.I., Que., Sask., Yukon; Alaska, Colo., Ill., Mich., Minn., N.Dak., S.Dak., Utah, Wyo.; Europe; Asia. The sterile shoots of Stellaria crassifolia (described as forma gemmificans Norman) form fleshy terminal buds under suitable conditions of temperature and day length. These propagules survive under the snow and are readily dispersed in the spring runoff.
Leaf shape and size vary considerably. Leaves tend to be smaller and wider in exposed habitats, and longer and narrower in sheltered, more favorable habitats. Plants with pubescent margins to the sepals are referable to var. eriocalycina Schischk.
Stellaria crassifolia is often confused with S. humifusa, but the former is a much more slender, delicate species with long pedicels that are sharply angled below the capsule.
Perennial herb with slender rhizomes, straggling or mat-forming 1 - 30 cm tall Stem: widely branched, four-angled. Leaves: opposite, stalkless or nearly so, 0.5 - 2 cm long, 1 - 2.5 mm wide, broadly elliptic to lance-shaped to narrowly lance-shaped with a tapering base, one-veined. The leaf size and shape are quite variable depending on the habitat. Flowers: usually solitary, often nodding, white, 5 - 8 mm long, subtended by a pair of bracts and sometimes one or two pairs of bractlets. Stalk upright, becoming curved at apex, to 4 cm long. Stamens five or ten. Styles three. Sepals: five, distinct, green, 2 - 3.5 mm long, narrowly triangular to lance-shaped with a more or less pointed tip, three-veined, scarious-margined (dry, thin, and membranous). Petals: five, white, 2.5 - 5 mm long, equal to or slightly longer than sepals. Fruit: a dehiscent capsule, opening by six valves, straw-colored, 4 - 5 mm long, longer than sepals, ellipsoid to egg-shaped with a blunt apex. Seeds reddish brown, about 1 mm wide, rounded to kidney-shaped, laterally compressed, wrinkled.
Similar species: The similar Stellaria graminea and S. longifolia differ by having hairy-fringed leaves (at their base), flowers that grow in terminal clusters, and bracts with scarious margins.
Habitat and ecology: Very rare in the Chicago Region, and has not been reported in many years. Found in wet, cold places, often along streams and marshes.
Occurence in the Chicago region: native
Etymology: Stellaria comes from the Latin words stella, meaning star, and -aria meaning "pertaining to," referring to the shape of the flowers. Crassifolia means "thick foliage."
Low, matted or erect, somewhat fleshy, glabrous perennial 1-2 dm; lvs soft, lanceolate or lance-elliptic, 1-2 cm נ1-2.5 mm, usually shorter than the internodes; fls mostly solitary, usually nodding; pedicels subcapillary, 1-2 cm; sep at anthesis mostly 2-3(3.3) mm, lanceolate, obtuse or acutish; pet surpassing the sep; fr ovoid, distinctly surpassing the sep; seeds 0.8 mm, oblong-orbicular, obviously (but not strongly) concentrically rugose-tuberculate; 2n=26. Streamsides, marshes, and other cold, wet places, mainly inland, but sometimes encroaching into the habitat of no. 11 [Stellaria humifusa Rottb.]; circumboreal, s. in Amer. to the Gasp顰eninsula, Mich., Minn., Colo., and Calif. June-Aug. (Alsine c.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.