Erect annual (3–)7–30 cm high; softly appressed pubescent. Basal leaves linear-oblanceolate, 20–50 x 3–5 mm, cauline leaves often larger. Inflorescence raceme-like, commonly forked at base; pedicels up to 17 mm long. Calyx oblong to turbinate, 6–8 x 4–5 mm, 10-veined, shortly pubescent, teeth 3 mm long, acuminate, keeled; petals absent or up to 8 mm long, deeply 2-fid, white or pink. Capsule c. 5 x 4 mm on 3 mm long carpophore. Seeds reniform, c. 1 mm long, dorsal surface deeply grooved with marginal wings, ± smooth, dark brown.
Range
N2, 3 Mediterranean weed now naturalised in many other parts of world.
Plants with petals exserted from the calyx are placed in var. grandiflora but the division from var. apetala, with petals lacking or included within the calyx, seems completely arbitrary as both often occur within the same population.