Walnut Family - Species Of Walnuts

Six species of walnuts occur in North America. The black walnut (Juglans nigra) and butternut (J. cinerea) are widespread in eastern North America. The little walnut (J. microcarpa) and Arizona walnut (J. major) range into Texas and Arizona and south into Mexico. The California walnut (J. californica) and Hinds walnut (J. hindsii) have relatively localized distributions in southern California. The English walnut (J. regia) is native to Europe and Asia but has been widely planted in North America.

Twelve native species of hickories occur in North America. The most famous species is the pecan (Carya illinoensis). This species occurs naturally throughout the central United States and south through eastern Mexico, but is now cultivated more widely throughout the eastern United States. Other species that are widespread in Pecans growing on a tree (above). Ripened pecans showing nut meat (below). JLM Visuals. Reproduced by permission.
southeastern North America are the shagbark hickory (C. ovata), mockernut hickory (C. tomentosa), pignut hickory (C. glabra), and bitternut hickory (C. cordiformis).