A large tree (Carya illinoensis) of the family Juglandaceae, and the nut from this tree. Native to valleys of the Mississippi River and tributaries as far north as Iowa, to other streams of Texas, Oklahoma, and northern and central Mexico, this nut tree has become commercially important throughout the southern and southwestern United States and northern Mexico. Limited plantings have been made in other regions, being reported of interest in such diverse areas as Arizona and California, South Africa, Israel, Brazil, and Peru. The tree's major importance is in areas with a long growing season of over 200 days and midsummer average temperatures of 79°F (26°C) or higher, though a few early-ripening cultivars are grown in slightly cooler regions. There are different cultivars for arid, irrigated regions and humid summer regions. The United States cultivars have an indistinct winter chilling requirement but fruit best where the coldest winter month averages less than 61°F (16°C).