—Description of Mandrake from Witchpedia.
—Description of Mandrakes from Strange Notebook
A Mandrake (マンドレイク Mandoreiku ) is a carnivorous plant which has a humanoid-shape root that, if uprooted, unleashes a terrible shriek that can kill non-magical humans. It is a very common ingredient for potions.
A full-grown Mandrake appears as a plant with a long green stem, several thorny vines used as prehensile tentacles to ensnare prey or enemies who dare to approach it, and a flower of bright purple colors that opens to unveil a large glowing mouth to swallow the captured prey whole. It begins to develop its flower and vines sometime after reaching the age of 5 years, given that Sucy's 5-year-old Mandrake in the manga still lack them.
Its roots on the other hand, resemble a human with appearance depend on its age; yonger mandrakes' barely resembles a human baby while adult ones a full-grown man. When unearthed, the root will release a powerful scream that can kill any ordinary human or animal who hear it as the form of defensive mechanism. The lethality of the scream also depends on the age: younger mandrakes would only render the victim unconscious while older ones (5 years old and upwards) can cause death in seconds.
Mandrakes are typically found in Arcturus Forest, though some also flourished in Mountain Ankaa, Shaula Desert, and Mimosa Forest as well.
As potion ingredient
Young roots can be used to make potions capable of restoring the magical power of a witch and the mature ones may even temporarily make her stronger than usual. But cautions must be taken when handling overflowing power from consuming potion derived from older mandrakes: Lack of control with overflowing magic would be disastrous.