Annual, pilose to vinous. Stems erect, 10-40 cm high, with spreading long eglandular hairs with or without sessile oil globules. Leaves 10-30 x 4-10 cm, oblong-spathulate or elliptic, entire or near apex crenulate, lowermost shortly petiolate, upper sessile. Inflorescence often extending almost the whole length of stem. Verticillasters 6-20, in axils of leaves, 3-6-flowered, mostly remote; uppermost leaves sometimes yellowish. Flowers yellow, almost sessile. Calyx c. 8 mm, green, with long and shorter eglandular hairs; teeth equal, oblong-ovate, c. 3 mm long terminating in a c. 2 mm mucro; tube 10-nerved, cylindrical-tubular; in fruit calyx scarcely expanded and turning brown, with erect-spreading teeth. Corolla shorter than calyx, c. 6-7 mm, vinous or pilose, yellow turning brownish black. Staminal thecae small, reduced. Nutlets pale brown, c. 1.9 x 1 mm, greyish brown obovate, apically rounded, with fine raised reticulations.