Fumariaceæ, an order of dicotyledonous herbs, allied to Papaveraceæ, of which they may be regarded as specialised forms. There are about a hundred species, mostly palæarctic, and mostly weeds, but some of great beauty (see DICENTRA). Several species of Fumaria and Corydalis are natives of Britain. The Common Fumitory (Fumaria officinalis) is a very common annual weed in gardens and corn-fields, rank, yet of rather delicate and beautiful appearance, and easily extirpated. It was formerly much employed in medicine, as also in dyeing, and as a source of potash.

(Fumaria officinalis).