Annual, biennial, or perennial, taprooted, caulescent, sometimes (not in Australia) suffruticose herbs, glaucous; sap yellow. Stems leafy, branching. Basal leaves rosulate, petiolate; cauline leaves alternate, sessile; blades pinnately lobed or unlobed, dentate or sometimes sinuate or entire. Flowers solitary, axillary or terminal; sepals 2; petals 4; ovary 2-locular; style absent or indistinct, stigma 2-lobed. Capsules erect, sublinear, 2-valved, dehiscing from the apex or base; seeds many, dark brown, reticulate-pitted, embedded in a pithy septum, aril absent.
About 25 species, native to Europe and central and south-western Asia; 2 species introduced in Australia.