Conopodium majus is a small perennial herb, whose underground part resembles a chestnut and is sometimes eaten as a wild or cultivated root vegetable.
The plant has many English names (many of them shared with Bunium bulbocastanum, a related plant with similar appearance and uses) variously including kippernut, cipernut, arnut, jarnut, hawknut, earth chestnut, groundnut, and earthnut. From its popularity with pigs come the names pignut, hognut, and more indirectly Saint Anthony’s nut, for Anthony the Great or Anthony of Padua, both patron saints of swineherds. (See groundnut, earthnut, and hognut for other plants which share these names.)
It has a smooth, slender, curving stem, up to 1 m high, much-divided leaves, and small, white flowers in many-rayed terminal compound umbels.
The rounded “nut” (inconsistently described by authorities as a tuber, corm, or root) is similar to a chestnut in its brown colour and its size (up to 25 mm in diameter), and its sweet, aromatic flavour has been compared to that of the chestnut, hazelnut, sweet potato, and Brazil nut. Palatable and nutritious, its eating qualities are widely praised, and it is popular among wild food foragers, but it remains a minor crop, due in part to its low yields and difficulty of harvest.