Annual aromatic herb to c. 1 m tall; stems branched, glandular-scaly, puberulent (hairs septate), occasionally all glabrous. Petiole c. 3-25 mm long; lamina 2.5-13 × 1-5 cm, lanceolate, narrow-ovate or elliptic, usually deeply serrate-dentate, glabrous or puberulent, dotted with sessile glands below; base cuneate; apex acute or subacute. Infls long-paniculate, axillary or terminal, efarinose; cymes (glomerules) in sessile clusters along branches; infl. lvs subtending cymes small, linear to oblanceolate, entire or sinuate. Perianth segments 0.5-1 mm long, valvate or slightly imbricate, glabrous or puberulent, green with narrow hyaline margin, not keeled on back. Fr. incompletely invested by perianth; pericarp easily removed. Seed horizontal or vertical, 0.6-0.9-(1.2) mm diam., subglobose to subreniform; margins rounded; testa glossy dark brown, smooth.