Aromatic annual, 5-80 cm, with short hairs and sessile glands. Stems erect, sparingly branched in middle, main axis longer than branches. Leaf blade green to yellowish green, to 8.5 cm, elliptic-ovate, pinnatifid with 3-5 broad lobes and several teeth on each side. Inflorescence elongate, not more than 5 cm wide, terminal, composed of mostly leafless dense dichasial cymes, or axillary with smaller cymes. Terminal flowers larger and flowering earlier than lateral ones. Perianth segments 5, c. 1 x 0.5 mm, elliptic to ovate, acuminate, free to base, often not contiguous at base, herbaceous with membranous margins, sometimes purple, with cristate glabrous keels, margins with sessile glands. Stamens 1-5. Stigmas 2. Pericarp free. Seeds horizontal, black, 0.6-0.8 mm, round in outline, margin rounded; testa uneven, with shallow small pits.