Description

Key Characters:

Growth Form: Low annual or perennial herbs.

Stems: Stems ascending or erect, stems often swollen at the nodes, usually many-branched.

Roots:

Leaves: Leaves simple. Opposite or whorled with 4 leaves per node. Blades obovate to orbicular or oblong. Base leaf bases often connate around the stem. Margins entire. Petiolate. Stipules dry and membranous.

Flowers: Flowers numerous in short, congested cymes. Cymes subtended by scarious bracts. Internal nectary ring present, often subtended by a number of bracts. Flowers bisexual (perfect), actinomorphic. Calyx of 5 sepals, ± keeled, margins scarious, distinct, nearly distinct, or connate into a conspicuous tube. Corolla of 5 petals, white, shorter than sepals, margins entire or emarginate; notched, cleft, or sometimes fibriate or divided, sometimes sharply differentiated into an expanded part and a basal claw, then often with 2 small outgrowths present at the juncture of the limb and claw. Stamens 1–5, distinct or adnate to petals at base to form a short tube, which may be adnate to the gynophore or sometimes adnate to lower part of calyx, petaloid staminodes sometimes present; anthers dithecal, opening by longitudinal slits. Ovary superior.

Fruit: Capsules 3–valved; the valves twisting after dehiscence. Seeds several; ovoid; usually ornamented on the surface; perisperm starchy; hard or rarely soft; true endosperm absent.

Ploidy:

Habitat:

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