black salsify

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

• noun A European plant (Scorzonera hispanica) in the composite family, having yellow flowers and a large, edible root.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A perennial member of the sunflower family (Asteraceae), cultivated as a root vegetable; Scorzonera hispanica.

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

• noun long black salsify
• noun perennial south European herb having narrow entire leaves and solitary yellow flower heads and long black edible roots shaped like carrots