Description

Key Characters:

Growth Form: Perennial herbs of saltwater.

Stems: Stems creeping, rooting at the nodes, each node with 2 scales, 1 embracing the stem, the other embracing a lateral, usually undeveloped shoot bearing the leaves.

Roots:

Leaves: Leaves simple. Opposite. Blades linear, lanceolate, oblong–elliptic, ovate, or sometimes spatulate. Margins entire to serrulate. Petiolate or sessile. Stipules absent.

Flowers: Flowers borne on an axillary shoot bearing scales and 1 or more pairs of leaves terminated by the inflorescence, solitary or rarely 1 staminate and 1 pistillate flower enclosed in a sessile spathe, consisting of 2 distinct, membranous bracts. Flowers unisexual (and the plants monoecious or dioecious). Pistillate flowers sessile or subsessile, with a long hypanthium with 3 reduced tepals at apex. Stamens 3, alternate with the tepals; anthers dithecal or quadrithecal, dehiscing lengthwise. Staminate flowers pedicellate. Ovary inferior, ovary ellipsoid or ovoid, 1-celled; styles 3–5, linear.

Fruit: Fruit ovoid or globose; beaked. Seeds few to numerous; globose or subglobose.

Ploidy:

Habitat: Marine.

Elevation Range: