There are about 15 edible varieties of walnuts, foremost among them is the Persian or English variety. This flavorful and popular variety originated in the Middle East and does not grow in England. They were called “English” because it was the English merchants who transported the nuts to the colonies. Today, this variety is produced mostly in California. English walnuts have a thin shell that is easily cracked, and the curly nutmeat halves have a sweet flavor with a touch of the bitterness and astringency of the golden to dark-brown edible skin. Other varieties include the black or American walnut, Chinese walnut, Japanese walnut, and the butternut or white walnut. Black walnuts were a Native American staple, with a sweet flavor and a hard, sticky shell that protects dark-skinned white nutmeats.