Description

Key Characters:

Growth Form: Annual herbs 10–2–(–30) dm tall.

Stems: Stems often tinged reddish, erect, occasionally ascending, branched, striate, glabrous to moderately pubescent with multicellular hairs.

Roots:

Leaves: Leaves simple. Alternate. Blades lanceolate to ovate or rhombic, blades 3–19(–30) cm long, 1.5–8(–12) cm wide. Lower surfaces glabrous to sparsely pilose along the margins and veins. Margins entire or sinuate. Petioles 0.5–15 cm long. Stipules absent.

Flowers: Flowers in axillary and terminal spikes, both sexes mixed throughout the spikes. Bracts and bracteoles deltate–ovate, tipped with a long, pale brown to reddish awn. Flowers unisexual; plants monoecious. Calyx of 5 sepals, yellowish, green, reddish, or purple, 1.5–3.5 mm long, lanceolate or oblong, apex acute, often awn-tipped, sometimes the apex of pistillate flowers blunt, only the midrib green. Corolla (petals) absent. Stamens (2)3–5, distinct; anthers dithecal. Ovary superior, 2–3(4)-carpellate, the carpels connate to form a compound, 1-celled ovary; ovule placentation basal, free-central, or rarely apical; style 1, often lobed; stigmas (2)3.

Fruit: Utricles with circumscissile or irregularly dehiscient; or indehiscent; 2–3 beaked at apex.; subglobose to ovoid; sometimes with a short; inflated or narrow and smooth neck below base of style; 2–3 mm long; dehiscent with a circumscissile lid; the lid smooth. Seeds 1 per fruit; the surface usually lustrous; endosperm essentially absent; black; sometimes shiny; compressed; 0.8–1.3 mm long; faintly reticulate near the margins.

Ploidy: 2n = 17; 24; 32

Habitat:

Elevation Range: