Cunningham's Encyclopedia of Magical Herbs - Scott Cunningham 1985
Walnut
The Herbs

(Juglans regia) Lt
Folk Names: Carya, Caucasian Walnut, English Walnut, Tree of Evil, Walnoot
Gender: Masculine
Planet: Sun
Element: Fire
Powers: Health, Mental Powers, Infertility, Wishes
Ritual Uses: Witches were supposed to dance beneath walnut trees in Italy during their secret rites.
Magical Uses: When carried, walnuts strengthen the heart and ward off rheumatism pains. They also attract lightning, so don’t carry one in an electrical storm.
If anyone gives you a bag of walnuts, you will see all your wishes fulfilled.
When placed in a hat or around the head, walnut leaves prevent headaches and sunstroke.
If a woman about to be married wishes to delay any “blessed events” she should place in her bodice as many roasted walnuts as correspond to the number of years she wishes to remain childless. She must do this on her wedding day.