Walnut. Walnut. Scientific classification Kingdom: Plantae Division: Magnoliophyta. Genus: Juglans L. Species. From Wikipedia, the free encycloped

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1 Walnut Frm Wikipedia, the free encyclped Walnut Sht and nut f Juglans regia Scientific classificatin Kingdm: Plantae Divisin: Magnliphyta Class: Order: Family: Genus: Magnlipsida Fagales Juglandaceae Juglans L. Species

2 Walnuts (genus Juglans) are plants in the walnut family Juglandaceae. They are deciduus trees, 10-40m tall, with pinnate leaves 20-90cm lng, with 5-25 leaflets; the shts have chambered pith, a character shared with the wingnuts (Ptercarya) but nt the hickries (Carya) in the same family. Walnut sht cut lngitudinally t shw chambered pith. Scale in mm. The 21 species in the genus range acrss the nrth temperate Old Wrld frm sutheast Eurpe east t Japan, and mre widely in the New Wrld frm sutheast Canada west t Califrnia and suth t Argentina. The Latin name Juglans derives frm Jvis glans, "Jupiter's nuts", the nut fit fr a gd. Walnuts are used as fd plants by the larvae f sme Lepidptera species including Brwn-tail, Cmmn Emerald, Emperr Mth, The Engrailed and the Clephra casebearers C. laticrnella (recrded n J. nigra) and C. pruniella. The wrd walnut derives frm Old English wealhhnutu, literally "freign nut", wealh meaning "freign" (wealh is akin t the terms Welsh and Vlach; see *Walha and Histry f the term Vlach). The walnut was s called because it was intrduced frm Gaul and Italy. The Late Latin name fr the walnut was nux Gallica, "Gallic nut". Species and classificatin Sect. Juglans. Leaves large (20-45 cm) with 5-9 brad leaflets, hairless, margins entire. Wd hard. Sutheast Eurpe t central Asia. Juglans regia L. (J. ducluxiana Dde, J. fallax Dde, J. rientis Dde) - Persian Walnut Juglans sigillata Dde - Irn Walnut (dubtfully distinct frm J. regia) Sect. Rhyscaryn. Leaves large (20-50 cm) with slender leaflets, finely pubescent, margins serrated. Wd hard. Nrth America, Suth America. Juglans australis Griseb. (J. bliviana Dde) - Argentine Walnut Juglans brasiliensis Dde - Brazilian Walnut

3 Juglans califrnica S.Wats. - Califrnia Walnut Juglans hindsii (Jepsn) R.E.Smith - Hinds' Walnut Juglans hirsuta Manning - Nuev Len Walnut Juglans jamaicensis C.DC. (J. insularis Griseb.) - West Indies Walnut Juglans majr (Trrey) Heller (J. ariznica Dde, J. elaepyrn Dde, J. trreyi Dde) - Arizna Walnut Juglans majr var. glabrata Manning Juglans micrcarpa Berlandier (J. rupestris Engelm.) - Texas Walnut r Little Walnut Juglans micrcarpa var. stewartii (Jhnstn) Manning Juglans mllis Engelm. - Mexican Walnut Juglans netrpica Diels (J. hnrei Dde) - Andean Walnut Juglans nigra L. - Black Walnut Juglans lanchana Standl. & L.O.Williams - Juglans peruviana Dde - Peruvian Walnut Juglans sratensis Manning - Juglans steyermarkii Manning - Guatemalan Walnut Juglans venezuelensis Manning - Venezuela Walnut Sect. Cardicaryn. Leaves very large (40-90 cm) with brad leaflets, sftly dwny, margins serrated. Wd sft. Nrtheast Asia, eastern Nrth America. Juglans ailantiflia Carr. (J. crdifrmis Maxim., J. siebldiana Maxim.) - Japanese Walnut Juglans cinerea L. - Butternut Juglans mandschurica Maxim. (J. cathayensis Dde, J. frmsana Hayata, J. hpeiensis Dde, J. stencarpa Maxim.) - Chinese Walnut r Manchurian Walnut

4 The best-knwn member f the genus is the Persian Walnut (Juglans regia), native frm the Balkans in sutheast Eurpe, suthwest & central Asia t the Himalaya and suthwest China. This is the species which is widely cultivated fr its delicius nuts. J. regia is als called English walnut because English merchant marines nce cntrlled its wrld cmmerce. The Black Walnut (Juglans nigra) is a cmmn species in its native eastern Nrth America, and is als widely cultivated elsewhere. The nuts are edible, but have a smaller kernel and an extremely tugh shell, and they are nt widely grwn fr nut prductin. The Butternut (Juglans cinerea) is als native t eastern Nrth America, where it is currently endangered by an intrduced disease, butternut canker, caused by the fungus Sircccus clavigignenti. Its leaves are cm lng, and the nuts val. The Japanese Walnut (Juglans ailantiflia) is similar t Butternut, distinguished by the larger leaves up t 90 cm lng, and rund (nt val) nuts. Hybrids Juglans x bixbyi Rehd. - J. ailantiflia x J. cinerea Juglans x intermedia Carr. - J. nigra x J. regia Juglans x ntha Rehd. - J. ailantiflia x J. regia Juglans x quadrangulata (Carr.) Rehd. - J. cinerea x J. regia Juglans x sinensis (D. C.) Rehd. - J. mandschurica x J. regia Juglans x paradx Burbank - J. hindsii x J. regia Juglans x ryal Burbank - J. hindsii x J. nigra

5 Uses The nuts f all the species are edible, but the walnuts cmmnly available in stres are frm the Persian Walnut, the nly species which has a large nut and thin shell. A hrticultural frm selected fr thin nut shells and hardiness in temperate znes is smetimes knwn as the 'Carpathian' walnut. The nuts are rich in il, and are widely eaten bth fresh and in ckery. Oil paint ften emplys walnut il as an effective binding medium, knwn fr its clear, glssy cnsistency and nn-txicity. Walnuts are als an excellent surce f mega-3 fatty acids, and have been shwn as helpful in lwering chlesterl. They need t be kept dry and refrigerated t stre well; in warm cnditins they becme rancid in a few weeks, particularly after shelling. Walnut nut husks are ften used t create a rich yellw-brwn t dark brwn dye that is used fr dyeing fabric and fr ther purpses. When picking walnuts, the husks shuld be handled wearing rubber glves, t avid dyeing ne's fingers.

6 Wd The Persian Walnut, and the Black Walnut and its allies, are imprtant fr their attractive timber, which (except in yung trees) is hard, dense, tight-grained and plishes t a very smth finish. The clr ranges frm creamy white in the sapwd t a dark chclate clr in the heartwd. When kiln-dried, walnut wd tends tward a dull brwn clr, but when air-dried can becme a rich purplish-brwn. Because f its clr, hardness and grain it is a prized furniture and carving wd. Walnut burls are cmmnly used t create bwls and ther turned pieces. The wd f the Butternut and related Asian species is f much lwer value, sfter, carser, less strng and heavy, and paler in clr. Parkland and garden trees Walnuts are very attractive trees in parks and large gardens. The Japanese Walnut in particular is grwn fr its huge leaves, which have a 'trpical' appearance. Walnuts are nt particularly well suited t smaller urban gardens. They drp numerus small twigs, leaves, branches r nuts, s are cnsidered "messy" by sme peple; the falling nuts in late summer and early autumn can be quite dangerus. Bth the fallen leaves and the rts secrete a substance called juglne which kills many ppular garden plants, such as tmat, apple and birch; all walnuts prduce juglne, but Black Walnut prduces larger amunts than ther species. Juglne appears t be ne f the walnut's primary defense mechanisms against ptential cmpetitrs fr resurces (water, nutrients and sunlight), and its effects are felt mst strngly inside the tree's "drip line" (the circle arund the tree marked by the hrizntal distance f its utermst branches). Hwever, even plants at a seemingly great distance utside the drip line can be affected, and juglne can linger in the sil fr many years even after a walnut is remved as its rts slwly decmpse and release juglne int the sil. An ld English rhyme states: A dg, a wife a walnut tree; The mre yu beat them The better they be.