Description

Key Characters:

Growth Form: Annual herbs.

Stems: Stems 1.5–3.5 dm long, glabrous.

Roots:

Leaves: Leaves simple. Alternate below, becoming opposite or ternate above. Blades spatulate, 1–1.4 cm long, 0.8–1.2 cm wide. Apex rounded. Base acute or cuneate. Surfaces bright green, caducous below, membranous, floral leaves smaller, often congested and reflexed. Margins entire. Petioles 0–0.6 cm long. Stipules absent.

Flowers: Flowers in cyathia solitary in the forks of the upper branches; pistillate flowers solitary, on a gynophore; staminate flowers in 5 groups or cymules, each with 1 to several flowers; peduncles 0.6– 1 mm long. involucre pale green, ca. 1 mm high, glabrous, glands 4, green, crescent–shaped, ca. 0.5 mm long, with slender or filiform horns 0.5–0.7 mm long. 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 broadly ovoid; shallowly 3–lobed; 1.8–2 mm long; 2–2.2 mm in diameter. Seeds gray; ovoid–oblong; weakly 6–angled; ca. 1.5 mm long; ca. 0.8 mm wide; coarsely pitted and minutely white tuberculate; carunculate.

Ploidy: 2n = 16

Habitat: Open or often shaded; disturbed sites; especially pastures.

Elevation Range: 300–2,300 m.