Herbs annual, 10-35 cm tall. Stems erect, much branched; branches green, fleshy. Leaves undeveloped, scale-like, to 1.5 mm, base united into a sheath, margin membranous, apex acute. Inflorescence shortly pedunculate, spicate, 1-5 cm. Flowers axillary, 3 per bract, middle flower larger, located slightly above lateral flowers. Perianth fleshy, obconic. Stamens exserted; anthers oblong. Ovary ovoid; stigmas papillate. Pericarp membranous. Seed cylindric-ovoid, ca. 1.5 mm in diam.; testa subleathery, hooked hispid. Fl. and fr. Jan-Aug.
"Annual, 1–5 dm, erect or the lower branches prostrate; scales below the spike obtuse or rounded; spikes erect or ascending, 2–6 × 1.5–3(–4.5) mm, the joints mostly 2–4 mm; fls broadly obovate, the central one much surpassing the lateral ones but reaching only to 0.5–1 mm below the node above; seeds 1.3–2 mm; 2n=18, 36. The commonest sp. of salt marshes; Que. to Fla., and in saline soil inland to Mich.; also Alas. to Calif., W.I., and widespread in the Old World. (S. herbacea; S. prostrata)"