Description

Key Characters:

Growth Form: Herbs.

Stems: Stems erect or prostrate, usually enlarged at the nodes.

Roots:

Leaves: Leaves simple. Opposite. Blades linear to narrowly obovate, thick, fleshy. Surfaces glabrous except in axils. Margins entire. Sessile and surrounding the stem. Sessile or short–petiolate. Stipules absent.

Flowers: Flowers in heads or spikes, these solitary or in clusters. Flowers bisexual (perfect), hypogynous. Calyx deeply 5-lobed. Corolla (petals) absent. Stamens 5; filaments connate basally; anthers 2-locular; pseudostaminodes absent. Ovary superior, 2–3(4)-carpellate, the carpels connate to form a compound, 1-celled ovary; ovule 1, placentation basal, free-central, or rarely apical; subglobose; style 1; stigmas 2–3.

Fruit: Utricles somewhat compressed; broadly ovoid; coriaceous; indehiscent. Seeds 1 per fruit; the surface usually lustrous; endosperm essentially absent; flattened; the surface smooth.

Ploidy:

Habitat: Mostly littoral in tropical and subtropical America.

Elevation Range: