Pl. Heermann., 46. 1854.
Herbs, annual, with taproot. Stems prostrate, 10–35 cm, glabrous or pilose. Leaves opposite; stipules distinct, subulate, 0.5–1.6 mm, glabrous or pilose; petiole 0.3–2 mm, glabrous or pilose; blade ovate to deltate or falcate, 2.3–13 × 1.5–6 mm, base asymmetric, usually cordate, rarely rounded, margins occasionally reddish, entire, often revolute, apex acute to obtuse, occasionally mucronate, surfaces glabrous or pilose; midvein conspicuous, lateral veins frequently visible abaxially. Cyathia solitary at distal nodes; peduncle 0.9–2.2 mm. Involucre campanulate, 1–2.5 × 1.3–2.4 mm, glabrous or pilose; glands 4, yellow becoming deep red, elliptic or oblong to orbiculate, 0.4–0.6 × 0.5–0.7 mm; appendages absent or whitish, orbiculate, 0.1–0.2 × 0.3–0.5 mm, distal margin entire. Staminate flowers 30–70. Pistillate flowers: ovary glabrous or pilose; styles 0.4–0.5 mm, 2-fid at apex. Capsules subglobose to broadly ovoid, 1.4–2.7 × 1.9–3.1 mm, glabrous or pilose; columella 1.4–2 mm. Seeds whitish gray to black, ovoid to oblong, terete to bluntly subangled in cross section, 1.1–1.7 × 0.8–1.3 mm, rugose or smooth.
Ariz., Calif., Idaho, Nev., Utah
Subspecies 2 (2 in the flora).