The Walnut is a sacred tree to Juno, a Goddess to whom the month of June in dedicated.
According to the Roman tradition, walnuts were thrown and donated to the spouses after the ceremony of the wedding as symbolic link with Juno: furthermore, as the fruit is protected by a woody shell, this also represents the protection of Juno on the family.
Like all trees, even walnut is an "inhabited" living being: its nymph is Caria (Kar or Ker ) who gives the sacred name to this tree. From the name of the nymph Kar or Ker comes the Latin term Kerebellum (brain) also for the resemblance of the walnut fruit with the brain according to the Science of Correspondence. Walnut is used in fact for its beneficial properties especially for the brain. The kernel, because of its resemblance to the brain, is sacred to Minerva while the shell is sacred to Janus for resemblance to a boat.
Ker, Kar, Caria is also connected with Carmenta beacuse the walnut is an oracle tree: at a walnut healers, shamans, and seers went to have inspiration, visions and prophecies. Moreover, walnut, thanks to this connection with Carmenta, is one of the fundamental trees at the base of the sacred alphabet and calendar.
This tree is linked also to the Great Mother: it represents life and death, light and darkness.
For all these reasons, especially because of its connection with these female Deities and Sacred Forces, Christianity has linked walnut to Satan, to sabers and witches.