Step 1 : Introduction to the question "Which is the world's oldest known vegetable?"
The oldest known vegetable is the one found in Stone Age settlements dating to 8,000 to 10,000 years ago. This historic vegetable is the pea. Humans have cultivated vegetables heavily over the millenia, but the vegetables eaten in prehistoric times differed from those we heartily consume today. Our ancient ancestors ate plants such as ferns and cattails, plants that modern man doesn't include on the menu. Vegetables such as kale, broccoli, cauliflower, cabbage, kohlrabi and Brussels sprouts were all commonly cultivated by early man. Source: Reference.com
