Herbs, usually annual, rarely biennial, with taproot. Stems erect or ascending, unbranched or branched, 10–70 cm, glabrous. Leaves: petiole absent or to 0.2 mm; blade oblanceolate, oblong-oblanceolate, spatulate, or cuneate, 10–50 × 6–11 mm, base broadly attenuate to rounded or shallowly cordate-clasping, margins finely serrulate (usually distally), apex usually rounded to obtuse, occasionally slightly retuse or obcordate proximally, bluntly mucronate, surfaces glabrous; venation pinnate, midvein prominent. Cyathial arrangement: terminal pleiochasial branches 3(–5), each 1–3 times 2-branched; pleiochasial bracts broadly ovate to ovate-oblong, shorter and wider than distal leaves; dichasial bracts distinct, broadly ovate, ovate-triangular, or ovate-elliptic, base cordate-clasping or subcordate to rounded, margins serrulate, apex rounded to obtuse or acute; axillary cymose branches (0–4)5–12. Cyathia: peduncle 0.3–1(–1.5) mm. Involucre campanulate to cupulate, 0.6–1(–1.5) × 0.8–1.2 mm, glabrous; glands 4–5, elliptic, oblong, to slightly reniform, 0.2–0.6 × 0.4–1 mm; horns absent. Staminate flowers 3–10. Pistillate flowers: ovary glabrous; styles 0.8–1.5 mm, 2-fid. Capsules depressed-globose, 2–3.5 × 4 mm, 3-lobed; cocci rounded, verrucose, verrucae 0.1–0.2 mm, glabrous; columella 1.4–2.2 mm. Seeds red-brown to dark purple, occasionally ± glaucous, broadly ellipsoid-ovoid to nearly globose, 1.3–2.5 × 1.5–1.8 mm, smooth, reticulate, or finely low-ridged; caruncle irregularly reniform to round, subconic to lenticular, 0.3–0.4 × 0.5–0.6 mm.
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Glabrous annual, 1–6 dm, often branched from the base; cauline lvs oblong-spatulate, 1–4 cm, obtuse, finely serrulate, the upper truncate or even subcordate at the sessile base; lvs subtending the umbel similar; lvs of the umbel shorter and relatively wider, broadly oblong to ovate or deltoid-ovate; rays of the primary umbel commonly 3, repeatedly dichotomous; involucre delicate, 0.8 mm; ovary and fr beset with numerous conic to cylindric processes, the fr 2.5 mm; seeds thick-lenticular, 1.5–1.8 mm, marked with a reticulum of fine, sharp, low ridges. Prairies, barrens, and rocky hills; Minn. and Mo. to Mont. and Tex., w. to the Pacific. May, June. (E. dictyosperma; Tithymalus arkansanus; T. missouriensis; Galarhoeus a.; G. m.)