Description

Key Characters:

Growth Form: Robust annual herbs.

Stems: Stems (1–)2–8 dm long, glabrous to pilose.

Roots:

Leaves: Leaves simple. Alternate below, opposite above. Blades broadly ovate, elliptic, obovate, or panduriform, rarely linear, blades 4–12 cm long, 0.3–7 cm wide. Apex acute, short-acuminate, or short-cuspidate. Base rounded to cuneate. Surfaces glabrous or pilose, green, sometimes floral leaves white or with splotches of purple at base, never red. Margins entire to coarsely serrate. Petioles (0.5–)1–4 cm long. Stipules absent or minute and gland-like.

Flowers: Flowers in cyathia in dense terminal cymes; pistillate flowers solitary, on a gynophore; staminate flowers in 5 groups or cymules, each with 1 to several flowers. involucre 2–2.5 mm high, glabrous, gland 1, cup–shaped with a circular opening, without an appendage. Flowers unisexual and highly reduced. Calyx (sepals) absent. Corolla (petals) absent. Male flower reduced to a single stamen, with an articulation at junction of pedicel and filament, subtended by slender bracteoles. Ovary superior, 3-carpellate; ovules 1 per cell, anatropous.

Fruit: Capsules subglobose; 3–4 mm long; glabrous. Seeds dark brownish gray to black; sometimes mottled; truncate–ovoid; angled; 2–2.5 mm long; coarsely tuberculate; ecarunculate.

Ploidy: 2n = 28; 38; 54; 56

Habitat: Low elevation; dry; disturbed sites.

Elevation Range: