Herbs; nodes with 2 rows of 3--5 roots. Leaves: sheath 4--35 cm, margins not overlapping; blade to 2 m ´ 1--4 mm, margins entire, apex obtuse to truncate or rarely slightly notched; veins 3. Generative shoots 0.2--11 cm, nodes 1--2, proximal node when present with 1 leaf, sterile, distal node with 1 leaf and 1(--2) spathes. Inflorescences: peduncles 11--60 ´ 1--2 mm; staminate bract 4--5.5 ´ 2--3 mm; pistillate bract 4--8 ´ 1.5--3 mm, base not narrowed, apex truncate to acute. Fruits 4--5 ´ 5.5 mm.

Flowering and fruiting late spring and summer. Intertidal and upper part of sublittoral; -2 m; B.C.; Alaska, Calif., Oreg., Wash.; Mexico (in Baja California).