Lathyrus tuberosus

 Earthnut Pea Fabaceae

A charmingly old-fashioned member of the pea family, Lathyrus tuberosus is a scrambling perennial native across much of Europe and into western Asia. Armed with delicate tendrils, it climbs obligingly through neighbouring vegetation, producing handsome pinnate foliage and, in summer, clusters of bright pink to reddish-pink, pea-like flowers with a distinctly sweet fragrance.

Its greatest botanical curiosity is underground. The plant produces small, knobbly tubers on its roots, which have a long history of being eaten in parts of Europe. Known variously as earthnut, tuberous pea or earth chestnut, the tubers are edible when cooked and have been described as pleasantly sweet, with a flavour reminiscent of chestnuts or sweet potatoes. They were historically roasted, boiled or otherwise prepared as a food, although they are decidedly more fiddly to harvest than a potato.

Give it sun or light shade and a reasonably fertile, well-drained soil. Once established it can scramble through shrubs and herbaceous planting, making a particularly attractive—and edible—piece of botanical history.

Height: 90–150cm
Spread: 60–100cm
Flowering: June–August
Hardiness: H5, approximately -15 to -10°C
Position: Sun or partial shade
Soil: Fertile, well-drained soil