Description

Key Characters:

Growth Form: Plants perennial, often mat–forming, glabrous.

Stems: Stems ascending or, more frequently, procumbent, rooting at nodes, giving rise to secondary tufts or rosettes, few–to many-branched, slender.

Roots:

Leaves: Leaves simple. Alternate. Frequently in basal rosettes in younger plants. Axillary fascicles often present on procumbent stems; basal herbaceous; cauline not conspicuously connate basally, never forming an inflated cup, sometimes slightly fleshy. Basal leaves linear, 8–17 mm; cauline blade linear, 4–15 mm proximally, becoming shorter toward apex, 2.5–6 mm distally. Apex of basal leaves apiculate to somewhat aristate; cauline leaf apex apiculate to aristate. Base sessile. Surfaces of basal leaves glabrous; cauline leaf surfaces rarely with minute glandular cilia. Margins entire. 1-veined. Petioles absent. Stipules absent.

Flowers: Flowers solitary and terminal on the branches or few in cymes. Flowers bisexual (perfect), actinomorphic, axillary or terminal, 4-merous, occasionally 4-and 5-merous. Pedicels frequently recurved during capsule development, filiform, glabrous. 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. Corolla of (1–)4(–5) petals; petals orbiculate to elliptic, 0.8–1(–1.5) mm, shorter than or equaling sepals, or sometimes absent. Stamens 4(8). Ovary superior 1-celled; ovules numerous; styles as many as and alternate with the sepals.

Fruit: 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.

Ploidy: 2n = 22

Habitat: 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.

Elevation Range: 0–3500 m.