Description

Key Characters:

Growth Form: Nearly glabrous annual herbs.

Stems: Stems usually 4–angled.

Roots:

Leaves: Leaves simple. Opposite. Blades narrow. Margins entire. Sessile. Stipules minute or absent.

Flowers: Flowers small, 2 to several in axillary cymes. Flowers small, bisexual (perfect), sometimes cleistogamous flowers also present, actinomorphic or sometimes zygomorphic. Calyx teeth 4, usually with a small horn-shaped appendage in each sinus, valvate, appearing as lobes on the floral tube, often alternating with external appendages at the sinuses. Corolla of 4 petals, alternate with the sepals, distinct, attached at summit of or within floral tube, crumbled in bud, small, caducous, sometimes absent. Stamens 4–8, inserted at various levels on the floral tube; anthers dithecal, opening by longitudinal slits. Ovary superior, 2–4(–6)-carpellate, with as many cells, at least at base, rarely 1-celled, placentation axile, rarely parietal when 1-celled; ovules 2 to numerous, anatropous, ascending; style 1, usually somewhat persistent; stigma usually capitate.

Fruit: Capsules 2–4–celled; dehiscing irregularly. Seeds numerous; angled and minutely pitted; endosperm absent or very scanty.

Ploidy:

Habitat:

Elevation Range: