A herb, erect, slender, simple or branched, up to 16 in. high, sometimes from a creeping base, glabrous
Annual herb with fleshy pinkish stems, (3–)5–25(–40) cm. tall, unbranched or branched from the lower 1–3 nodes, sometimes reaching flowering with the cotyledons persistent; apparently monoecious.
Stems glabrous, eglandular, with minute linear cystoliths in epidermis.
Leaves of a pair equal, but usually increasing in size from the lower nodes to the top of the plant, while the length of nodes and petioles decreases, so the uppermost 2 pairs appear to be verticillate and almost sessile; stipules thin, membranous, persistent, ovate to subcircular, up to ± 4 mm. long and 5 mm. wide, with subcordate base and rounded apex; petioles of lower leaves 0.4–2.5 cm. long, of upper, subverticillate leaves 0.2–0.5 cm. long; lamina ovate, in the lower leaves 0.9–3 cm. long, 0.6–2.8 cm. wide, in the upper leaves up to 3.5 cm. long and 3 cm. wide, ovate, rarely elliptic–subcircular, base cuneate to truncate, margin serrate, with (4-)5–12 teeth on each side, apex blunt to acute, rarely acuminate, with a large terminal tooth; basal pair of lateral nerves clearly marked, reaching 3rd–4th tooth from apex, giving off lateral nerves to the lower teeth, other lateral nerves indistinct; upper surface with appressed hairs and fine linear cystoliths, lower surface glabrous or with scattered hairs on the nerves, and with scattered hydatodes.
Inflorescences in the axils of the upper leaves (the largest inflorescences corymb-like, forming a cross-shaped figure at the stem-apex, but consisting of 4 inflorescences in the axils of the 4 uppermost leaves), paniculate, with flowers in cymose glomerules; ♂ inflorescences or partial inflorescences apparently rare, restricted to the axils of the upper leaves, where they occur together with purely ♀ inflorescences, with a structure as described above.
Achene broadly ovate, compressed, smooth or ± verrucose, brown, up to 0.8 mm. long.
Female flowers: pedicel up to 1 mm. long; perianth (3–)4-merous, with 1 large, longitudinally crested segment and (2–)3 very short ones, visible only as crenation on a short, basal tube; 4 hyaline, staminodal scales present, ± enclosing the ovary.
Male flowers in small clusters on axes up to 0.8 cm. long; pedicels 1–2 mm. long; perianth with 2 lobes and 2 stamens.
Stems to c. 20 cm. tall, fleshy, pinkish, glabrous; leaves of a pair equal, increasing in size upwards, the four uppermost forming an apparent whorl at the top of the stem by shortening of the uppermost internode.
Erect annual herbs, monoecious (or dioecious by abortion).
Male inflorescences small and insignificant, in the axils of the leaves below the apical whorl, sometimes absent, sometimes with a few female flowers, or a few male flowers in the apical inflorescence; male flowers almost sessile, 2–4-merous, with stamens in the same number as tepals.
Stipules up to 4 mm. long, broadly ovate, membranous, persistent.
Leaves petiolate, 0.7–2 x 0.4–1.5 cm., ovate, apex acute or short acuminate; base ± broadly cuneate; margin serrate with 5–12 teeth per side, lamina glabrous on both sides.
Achene c. 1.5 mm. long, broadly ovoid, compressed, smooth or ± verrucose.