scurvy grass

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of various plants of the genus Cochlearia of the mustard family, especially the circumboreal species C. officinalis, having pungent fleshy foliage and formerly used to prevent or treat scurvy.
• noun Any of various other plants formerly used to prevent or treat scurvy.

from The Century Dictionary.

• noun A cruciferous plant, Cochlearia officinalis, of northern and western Europe and arctic America: an antiscorbutic and salad plant. Locally called scrooby - or scruby-grass.
• noun One of the winter cresses, Barbarea præox, a European plant cultivated as a winter salad, becoming wild in parts of the United States.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a widely distributed Arctic cress reputed to have value in treatment or prevention of scurvy; a concentrated source of vitamin C
• noun any plant of the genus Barbarea: yellow-flowered Eurasian cresses; widely cultivated for winter salad