Herbs, annual, prostrate to erect, green to dark red, 0.5–8(–10) dm, glaucous. Stems decumbent to erect, green to dark red, usually striped, simple or branched; branches decumbent, ascending, or spreading. Leaves often tightly ascending, sometimes ± spreading; blade linear-lanceolate, adaxial surface flat, (5–)10–40 × 0.2–15 mm, usually widest proximal to middle, apex acute to apiculate. Glomes usually crowded in 1–6 cm compound spikes, 3–5(–7)-flowered; bracts subtending branches leaflike, often slightly broader than leaves, bracts subtending glome similar in shape to leaves, 2–12 × 0.8–1.5 mm, broadest proximal to middle, thin-margined basally. Flowers bisexual; perianth zygomorphic or irregular (1 or 3 segments usually larger), 1–4 mm diam.; perianth segments transversely winged proximally (continuously in disk or interrupted), rounded and keeled abaxially and/or horned or hooded distally; stigmas usually 2. Seeds dimorphic; lenticular, 0.8–1.7 mm diam., with seed coat black, shiny; or flat, 1–1.5 mm diam., with seed coat brown, dull. 2n = 36.
