Low, strongly grey-farinose annual, bad-smelling (like decaying fish), especially when rubbed between finger and thumb; main stem to 30 cm, erect to procumbent, without red colour, usually much branched especially basally, lowermost internodes short and lower branches often subopposite, to 70 cm long, ascending to prostrate. Leaf blade grey-farinose especially beneath, greener above, longer than or equal to petiole, 0.5-3 cm long, broadly trullate or broadly ovate to ovate, margin entire, in large leaves sometimes with a fairly acute angle on each margin at broadest part, base truncate to short attenuate, apex obtuse to acute. Inflorescence small, terminal and axillary, composed of loose, short panicles; glomerules small. Flowers perfect, or lateral ones often female. Perianth segments 5, connate to the middle or more, with rounded back. Stamens 5 or 0. Stigmas 2, short. Fruits falling with perianth. Pericarp ± adherent. Seeds horizontal, brownish-black, 0.9-1.2 mm in diameter, round in outline; testa almost smooth except for weak radial striae.

Fl. & Fr. Per.: April -- July (-- October).

Lectotype: ‘Habitat in Europae cultis oleraceis’, Herb. Linn. No. 313/18 (LINN!). Jafri & Raateb in Jafri & El Gadi, Fl. Libya 58: 15. 1978.

Gardens, fields, waste ground. 1500 m; Distribution: The Mediterranean area, C and E Europe, SW and southern C Asia; introduced in S Africa, N America and Australia.

The nasty smell of trimethylamine persists on herbarium material even several decades after by slightly moistening the plant and rubbing between finger and thumb. In addition to the smell, the leaf shape and the shape of inflorescence differentiate C. vulvaria from C. karoi and C. pamiricum.