a brief HISTORY OF
WALNUTS
by Philip McIntosh
Technically a type of stone fruit , walnuts have 21 different species and are considered the oldest tree nut used as human food .
Let ’ s get acquainted with the walnut .
All walnuts are members of the genus Juglans ( established by Linnaeus ), which is the old Roman word for walnut . The name Juglans derives from the Latin Jovis ( Jupiter ) and glans ( acorn ) meaning “ Jupiter ’ s acorn ,” indicating it was good to eat , since acorns were also widely consumed in early times .
Although there are 21 species in the genus , in Australia the Juglans regia , ( English walnut ) is the most common variety in backyards and for commercial purposes . By volume , the key production regions are the Riverina in New South Wales and the east coast of Tasmania . However , walnuts are also grown throughout Victoria , in cooler regions of southern New South Wales around Adelaide and the Riverland , and in south west Western Australia . Although they are cold tolerant , walnut trees do not do well at high temperatures and humidity . The English walnut , also known as the Persian walnut , is thought to be native to Asia ( Iran ) and parts of Europe , and made its way to Australia more than a century ago . Commercially , J . regia is preferred because of easier cultivation and an easier-to-crack shell . All walnuts are sizable deciduous trees with deep tap roots . The large leaves are pinnate , composed of five to eight leaflets with a single leaflet at the tip . The fruit are “ culinary nuts ” but not “ botanical nuts .” Technically a “ nut ” has a hard mostly seamless wall that does not open to release its seed . Walnut fruit are drupes , a type of stone fruit , but we ’ ll call them nuts . The nuts possess a hard segmented shell that encloses the meat . They develop inside a rind that comes off after ripening . Nuts from the English variety are considered milder in flavour than black walnuts . Walnut trees , especially black walnuts , are not exactly good neighbours as far as other plants are concerned . Pliny the Elder noted two thousand years ago that walnut trees were toxic to other plants . Walnuts exhibit allelopathy , the ability to produce a substance that is toxic or inhibitory toward other species .
The soil in the vicinity of a walnut tree is often rather bare , not supporting much in the way of other plant species . Walnut trees produce juglone , an organic compound that inhibits the growth of some species , while having no effect on others . Tomatoes , for example , are highly sensitive to juglone , while several shade-tolerant shrubs are not . In fact , there are more known juglone-tolerant plants than sensitive ones . What can you do with a walnut ? The trees themselves are majestic and long-lived ( 75-150 years ) and are much admired in both natural forests and landscapes . The rich brown heartwood of the walnut , especially black walnut , is an excellent material for making furniture , cabinets , floor boards , and paneling . Food-wise , walnuts have been around for a long time . According to some sources , walnuts are the oldest known tree nut used as human food . This is based on archeological evidence from about 7,000 years ago . At one location in France walnuts were apparently being roasted , perhaps to make them easier to open . Seems like easier-to-open nuts would have been consumed long before that .
Walnuts have the usual good nutritional rap sheet typical of many tree nuts . In general nuts are heart healthy , lower blood pressure , and help manage cholesterol . Walnuts are no exception and are on the high end of the nut-benefit scale with a particularly good combination of fats and fatty acids . They are also a good source of copper , iron , zinc , vitamin C , and niacin ( vitamin B3 ). Walnuts are comparatively high in calories though ( it ’ s those fats and fatty acids ) so don ’ t overdo it !
54 Maximum Yield