Mandrake refers to any plant from the Mandragora plant genus. Mandrakes often have a substance in them called bifurcation, and this substance is known to give this plant a humanlike figure. These plants are often used in rituals.
Many cultures have a different take on these plants. For example, many Hebrews considered this plant's fruits to be a symbol of love. The fruits of this plant were believed to be a cure for infertility, and they were highly valued by women because of this common-held belief. Mandrakes are also constantly mentioned in the Old Testament, particularly in Song of Songs.
However, in many other cultures, there is believed to be a darker side to these plants. It is commonly believed that if one were to pluck a mandrake out of the ground with its roots still intact, then that mandrake would make a horrid yell. Anyone within earshot of the yell would immediately drop dead.