The Juglandaceae are a plant family known as the walnut family. They are
tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only wood plants with se ...

s, or sometimes shrubs, in the order
Fagales The Fagales are an order (biology), order of flowering plants, including some of the best-known trees. The order name is derived from genus ''Fagus'', beeches. They belong among the rosid group of dicotyledons. The families and genera currently ...
. Members of this family are native to the
Americas The Americas (also collectively called America) is a landmass comprising the totality of North America, North and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World. Along with th ...

Eurasia Eurasia () is the largest continent A continent is any of several large landmass A landmass, or land mass, is a large region In geography Geography (from Greek: , ''geographia'', literally "earth description") is a ...

, and
Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern subregion of Asia, consisting of the regions ...

Southeast Asia
. The nine or ten genera in the family have a total of around 50 species, and include the commercially important
nut Nut often refers to: * Nut (fruit) A nut is a fruit In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist wh ...
-producing trees
walnut A walnut is the Nut (fruit), nut of any tree of the genus ''Juglans'' (family Juglandaceae), particularly the Persian or English walnut, ''Juglans regia''. A walnut is the edible seed of a drupe, and thus not a true botanical nut. It is com ...

pecan The pecan (''Carya illinoinensis'') is a species of hickory native to the southern United States and northern Mexico in the region of the Mississippi River. The tree is cultivated for its seed in the southern United States, primarily in Georgia ...

(''Carya illinoinensis''), and
hickory Hickory is a common name for trees In botany Botany, also called , plant biology or phytology, is the science Science (from the Latin word ''scientia'', meaning "knowledge") is a systematic enterprise that Scientific method ...

(''Carya''). The Persian walnut, ''
Juglans regia ''Juglans regia'', the Persian walnut, English walnut, Carpathian walnut, Madeira walnut, or especially in Great Britain, common walnut, is an Old World The Old World consists of Africa Africa is the world's second-largest and s ...

Juglans regia
'', is one of the major nut crops of the world. Walnut, hickory, and gaulin are also valuable timber trees while pecan wood is also valued as cooking fuel.


Members of the walnut family have large, aromatic leaves that are usually alternate, but opposite in '' Alfaroa'' and '' Oreomunnea''. The
leaves A leaf (plural leaves) is the principal lateral appendage of the vascular plant plant stem, stem, usually borne above ground and specialized for photosynthesis. The leaves, stem, flower and fruit together form the shoot system. Leaves are ...

are pinnately compound or ternate, and usually 20–100 cm long. The trees are
wind-pollinated Anemophily or wind pollination is a form of pollination Pollination is the transfer of pollen Pollen is a powdery substance consisting of pollen grains which are Sporophyte, microsporophytes of spermatophyta, seed plants, which produce ...
, and the flowers are usually arranged in
catkin A catkin or ament is a slim, cylindrical flower A flower, sometimes known as a bloom or blossom Image:Cerisier du Japon Prunus serrulata.jpg, Cherry blossoms in Paris in full bloom. In botany, blossoms are the flowers of stone fruit fruit tre ...

s. The fruits of the Juglandaceae are often confused with drupes but are accessory fruit because the outer covering of the fruit is technically an involucral bract, involucre and thus not morphologically part of the carpel; this means it cannot be a drupe but is instead a drupe-like nut.


The known living genera are grouped into subfamilies, tribes, and subtribes as follows: * Subfamily Rhoipteleoideae Reveal ** ''Rhoiptelea'' Diels & Hand.-Mazz. 1932 * Subfamily Engelhardioideae Iljinskaya 1990 ** '' Alfaroa'' Standl. 1927—gaulin ** ''Engelhardia'' Lesch. ex Blume 1825–1826—cheo ** '' Oreomunnea'' Oerst. 1856 * Subfamily Juglandoideae Eaton 1836 ** Tribe Platycaryeae Nakai 1933 *** ''Platycarya'' Siebold & Zucc. 1843 ** Tribe Juglandeae Rchb. 1832 *** Subtribe Caryinae D.E. Stone & P. S. Manos 2001 **** ''hickory, Carya'' Nutt. 1818—hickory and pecan **** ''Annamocarya'' A.Chev. 1941 (sometimes included in ''Carya'') *** Subtribe Juglandinae D.E. Stone & P. S. Manos 2001 **** ''Cyclocarya'' Iljinsk 1953—wheel wingnut **** ''Juglans'' L. 1753—walnut **** ''Pterocarya'' Kunth 1824—wingnut


Modern molecular phylogenetics suggest the following relationships:


{{Authority control Juglandaceae, Rosid families