Leaves all submersed, very narrow-linear, ± 1 mm wide, numerous transverse veins usually visible; stipules adnate below to leaf. Spike 2-4 cm long, discontinuous. Achenes rounded, without prominent keel or beak, light pinkish-brown.

Rhizome extensively creeping, forming swollen buds in autumn. Branches slender, much-branched, sts very long. Stipule adnate to lf-base, open but sheathing stem for 1–4 cm., the free ligular portion membr., c. 5 mm. long. Lvs all submersed, 5–12 cm. × c. 1 mm., entire, very narrow-linear, us. tapered to ± acute tip, membr., ∞ transverse veins us. visible. Peduncles slender, short or long. Spike discontinuous, 2–4 cm. overall, the lower whorls well separated. Achene c. 3 × 2.5 mm., light pinkish brown, rather plump and rounded, without prominent keel or beak.