Kohlrabi (also kohl-rabi) is a low and stout biennial. It originated in Germany around 4,000 years ago and is a member of the cabbage family (Gongylodes group). It is a cabbage that was selected for its swollen stems -- in German 'kohl' is cabbage and 'rabi' is turnip and it is so called because it has cabbage-like leaves and a turnip-like bulb above ground.
Varieties include White Vienna and Purple Vienna. Some varieties are food for cattle.