The turnip or white turnip (Brassica rapa subsp. rapa) is a root vegetable commonly grown in temperate climates worldwide for its white, bulbous taproot.
Like rutabaga, turnip contains bitter cyanoglucosides that release small amounts of cyanide. Sensitivity to the bitterness of these cyanoglucosides is controlled by a paired gene. Subjects who have inherited two copies of the “sensitive” gene find turnips twice as bitter as those who have two “insensitive” genes, thus may find turnips and other cyanoglucoside-containing foods intolerably bitter.