Matted pearlwort, sagine couchée

Sagina procumbens var. compacta Lange

Plants perennial, often mat-forming, glabrous. Stems as-cending or, more frequently, procumbent, rooting at nodes, giving rise to secondary tufts or rosettes, few- to many-branched, slender. Leaves: axillary fascicles often present on procumbent stems; basal frequently in primary rosettes in younger plants; blade linear, 8-17 mm, herbaceous, apex apiculate to somewhat aristate, glabrous; cauline not conspicuously connate basally, never forming an inflated cup, blade linear, 4-15 mm proximally, becoming shorter toward apex, 2.5-6 mm distally, sometimes slightly fleshy, apex apiculate to aristate, rarely with minute glandular cilia. Pedicels frequently recurved during capsule development, filiform, glabrous. Flowers axillary or terminal, 4-merous, occasionally 4- and 5-merous; calyx base glabrous; sepals elliptic to orbiculate, 1.5-(-2.5) mm, hyaline margins white, never purple tinged, apex obtuse to rounded, appressed during capsular development, divergent following dehiscence; petals (1-)4(-5), orbiculate to elliptic, 0.8-1(-1.5) mm, shorter than or equaling sepals, or sometimes absent; stamens 4 (8). Capsules (1.5-)2-2.5(-3) mm, slightly exceeding sepals, dehiscing to base. Seeds brown, obliquely triangular with distinct abaxial groove, (0.3-)0.4(-0.5) mm, smooth to pebbled. 2n = 22.

Flowering late spring-early fall. Weedy, wet or damp, gravelly or sandy soils along roadsides, sidewalk cracks, margins of paths or lawns, pond and lake margins, coastal rocks and sands, sea cliffs; 0-3500 m; introduced; Greenland; St. Pierre and Miquelon; B.C., N.B., Nfld. and Labr. (Nfld.), N.W.T., N.S., Ont., P.E.I., Que.; Alaska, Ark., Calif., Colo., Conn., Del., Idaho, Ill., Iowa, Maine, Md., Mass., Mich., Minn., Mont., N.H., N.J., N.Y., N.C., Ohio, Oreg., Pa., R.I., Utah, Vt., Wash., W.Va., Wis.; Europe; introduced in Mexico (Chiapas, México), Central America (Costa Rica, Guatemala), s South America (Bolivia, s Argentina), Asia (w Siberia), Antarctica (sub-Antarctic Islands).