What is 'sea kale'?

Crambe maritima (common name sea kale, seakale or crambe) is a species of halophytic flowering plant in the genus Crambe of the family Brassicaceae (Cruciferae), that grows wild along the coasts of Europe, from the North Atlantic to the Black Sea.

The plant is cultivated as a vegetable, related to the cabbage.

Along the coast of England, where it is commonly found above high tide mark on shingle beaches, local people heaped loose shingle around the naturally occurring root crowns in springtime, thus blanching the emerging shoots. By the early eighteenth century, it had become established as a garden vegetable, but its height of popularity was the early nineteenth century when sea kale appeared in Thomas Jefferson's Garden Book of 1809. It was also served at the Royal Pavilion in Brighton, when Prince Regent George IV of the United Kingdom (1762–1830) used it as a seaside retreat.