Description

Key Characters:

Growth Form: Plants densely to moderately pubescent, especially distal parts of stem and branches.

Stems: Stems erect, reddish near base, branched in distal part to simple 0.2–1.5(–2) m, underdeveloped or damaged plants rarely ascending to nearly prostrate.

Roots:

Leaves: Leaves simple. Alternate. Blades ovate to rhombic–ovate, 2–15 × 1–7 cm. Apex acute, obtuse, or slightly emarginate, with terminal mucro. Base cuneate to rounded-cuneate. Surfaces shortly hairy, but densely hairy abaxially. Margins entire, plane or slightly undulate. Petioles ½ to equaling blade. Stipules absent.

Flowers: Flowers in inflorescences terminal and axillary, erect or reflexed at tip, green or silvery green, often with reddish or yellowish tint, branched, leafless at least distally, usually short and thick. staminate flowers few at tips of inflorescences. bracts lanceolate to subulate, (2.5–)3.5–5(–6) mm, exceeding tepals, apex acuminate with excurrent midrib. Flowers unisexual; plants monoecious. Calyx of 5 sepals; sepals white, oblong or oblong-obovate, 2-2.5 mm, membranous, with a green midvein, apex acute or notched, with a mucro. Corolla (petals) absent. Stamens (3–)4–5. Ovary superior; stigmas 3.

Fruit: Utricles broadly obovoid to broadly elliptic; 1.5–2.5 mm; shorter than or subequal to tepals; smooth or slightly rugose; especially near base and in distal part; dehiscence regularly circumscissile. Seeds 1 per fruit; black to dark reddish brown; lenticular to subglobose–lenticular; 1–1.3 mm; smooth; shiny.

Ploidy: 2n = 34

Habitat: Banks of rivers; lakes; and streams; disturbed habitats; agricultural fields; railroads; roadsides; waste areas.

Elevation Range: 0–2500 m.