Juglandaceae

Juglandaceae represent a characteristic northern hemisphere family, in the New World going south to Central America (Mexico, Costa Rica, Guatemala, Panama, Cuba, Hispaniola and found S of the equator as fas as c. 30° S, absent from Africa, and overstepping the equator also in the Malaysian region where Engelhardia extends to Java and New Guinea. This distribution shows a remarkable resemblance with that of the Fagaceae-Castaneae which though absent S of the equator in the Americas, occur in Africa in the Mediterranean part only, and though rather well represented as far as New Guinea are also absent in Australia and the Pacific islands. A noteworthy detail of this parallel is that although both are well represented in the Himalayan region and the Indo-Chinese Peninsula no representative of either group is found in Ceylon and the Deccan Peninsula! Northwards the family extended much farther in Tertiary time and fossils are known from Sakhalin, E. Siberia to 61° N (where at present Juglans occurs to 51° N), also Alaska (pollen grains), Greenland, and Spitsbergen. Several genera which are now confined to East Asia or North America occurred in Europe from the Upper Cretaceous until the Pliocene but became gradually extinct there during the Pleistocene Ice Age. See also under Engelhardia.