Erect unbranched or sparsely branched annual herb 15–70 cm. tall; stems reddish, densely covered with short white spreading pubescence but eventually glabrescent beneath. Leaves in closely placed whorls of 2–3 but appearing densely verticillate due to reduced shoots in the axils, turning reddish; blades linear, 1–2.2 cm. long, 0.8–1.2 mm. wide, sharply pointed at the apex, narrowed to the base, glabrous save for the almost obsolete petioles; upper surface reticulate, the cells often obvious at × 10; stipule-sheath 0.5 mm. long with 1 seta 2 mm. long, pubescent. Flowers several in the axils of the upper 5–22 verticils of short leaves, the whole inflorescence 3–12 cm. long; pedicels very short; flowers unisexual or sometimes hermaphrodite . Male: calyx-tube ovoid, 1.5 mm. long, hairy around the rim but lobes ± obsolete; corolla cream; tube narrow, 1.8 mm. long; lobes elliptic-lanceolate, 2 mm. long, 1 mm. wide, with a few scattered hairs outside; anthers exserted 1.4 mm., ± 1–1.2 mm. of filaments showing; styles joined for 0.3 mm., lobes 1 mm. long. Female: calyx similar to ♂, lacking real lobes; corolla cream; tube small, 0.5–0.8 mm. long; lobes 0.5–1 mm. long, 0.2 mm. wide; styles joined for 1 mm., arms 0.6–1.3 cm. long, pubescent. Hermaphrodite: calyx-tube similar, hairy at apex; corolla greenish, tube ± 3 mm. long; lobes narrowly elliptic-lanceolate, 2.5 mm. long, 0.8 mm. wide, hairy outside; filaments exserted 2 mm.; styles joined at base for 0.8 mm., free arms 6.2 mm. long. Fruits pubescent or glabrous save at apex, the cocci 2 mm. long, 0.8 mm. wide, not crowned by the calyx-limb.
