Real Dictionary

mandrake in American English
a poisonous plant (Mandragora officinarum) of the nightshade family, found in Mediterranean regions: it has purple or white flowers and a thick root, often forked, formerly used in medicine for its narcotic and emetic properties
noun: a narcotic, short-stemmed European plant, Mandragora officinarum, of the nightshade family, having a fleshy, often forked root somewhat resembling a human form

mandrake in British English
noun: a Eurasian solanaceous plant, Mandragora officinarum, with purplish flowers and a forked root. It was formerly thought to have magic powers and a narcotic was prepared from its root