sea kale

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A European seashore plant (Crambe maritima) of the mustard family, having edible cabbagelike leaves. Also called scurvy grass.

Wiktionary

1. n. Crambe maritima, a halophytic perennial plant that grows wild along the coasts of Europe.

GNU Webster's 1913

1. n. (Bot.) a European cruciferous herb (Crambe maritima), often used as a pot herb; sea cabbage.
2. (Bot.) See under kale.

WordNet 3.0

1. n. perennial of coastal sands and shingles of northern Europe and Baltic and Black Seas having racemes of small white flowers and large fleshy blue-green leaves often used as potherbs