The Persian, often called English walnut, had been brought to Europe during Medieval times by traders from south central Asia. Its value as a nut and furniture wood crop was well known throughout the Old World by colonial times. Early Americans soon realized that the native American black walnut was just a bit different from its Eurasian relative. First of all, the New World tree grew bigger than its cousin. Secondly, its nut meat, while equally edible and nutritious, was stronger tasting. Thirdly, unlike the relatively easy to crack shell of the Persian walnut, the American’s shell was extremely hard, difficult to smash.
Ornamental and fruit-bearing trees, rarely shrubs, with deciduous, alternate, odd-pinnate leaves, and with inconspicuous greenish flesh, appearing with the leaves, the staminate in pendulous slender catkins, the pistillate in few- to many-flowered racemes; the fruit a large drupe, containing an edible nut.