Juglans regia

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English Walnut

Whole and shelled J. regia

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Fagales
Family:	Juglandaceae
Genus:	Juglans
Species:	J. regia

Binomial name

Juglans regia
L.

Juglans regia (the Common walnut, Persian walnut, or English walnut), is the original walnut tree of the Old World. It is native in a region stretching from the Balkans eastward to the Himalayas and southwest China. The largest forests are in Kyrgyzstan, where trees occur in extensive, nearly pure walnut forests at 1,000–2,000 m altitude (Hemery 1998)—notably at Arslanbob in Jalal-Abad Province.

Juglans regia is a large deciduous tree attaining heights of 25–35 m, and a trunk up to 2 m diameter, commonly with a short trunk and broad crown, though taller and narrower in dense forest competition. It is a light-demanding species, requiring full sun to grow well.

The bark is smooth, olive-brown when young and silvery-grey on older branches, with scattered broad fissures with a rougher texture. Like all walnuts, the pith of the twigs contains air spaces, the chambered pith brownish in colour. The leaves are alternately arranged, 25-40 cm long, odd-pinnate with 5–9 leaflets, paired alternately with one terminal leaflet. The largest leaflets the three at the apex, 10–18 cm long and 6–8 cm broad; the basal pair of leaflets much smaller, 5–8 cm long, the margins of the leaflets entire. The male flowers are in drooping catkins 5–10 cm long, the female flowers terminal, in clusters of two to five, ripening in the autumn into a fruit with a green, semi-fleshy husk and a brown corrugated nut. The whole fruit, including the husk, falls in autumn; the seed is large, with a relatively thin shell, and edible, with a rich flavour.

1 Cultivation and uses
2 Nutritional value
3 Etymology and other names
4 Folklore
5 References

[edit] Cultivation and uses

The walnut was introduced into western and northern Europe very early, by Roman times or earlier, and to the Americas by the 17th century. Important nut-growing regions include France, Serbia, Greece, Bulgaria, and Romania in Europe, China in Asia, California in North America, and Chile in South America. It is cultivated extensively for its high-quality nuts, eaten both fresh and pressed for their richly flavoured oil; numerous cultivars have been selected for larger and thin-shelled nuts.

The wood is of very high quality, and is used to make furniture and rifle stocks.

Walnut ink, made by boiling the whole fruit or letting it oxidize, then releasing onto the exterior, is dark brown in color and darkens as it oxidizes. It can also be used to stain wood.

[edit] Nutritional value

100 g shelled walnuts provide:

15.2 g protein
65.2 g fat:
- 6.1 g saturated fat
- 8.9 g monounsaturated fat
- 47.2 g polyunsaturated fat
13.7 g carbohydrates, including 6.7 g dietary fiber
0.34 mg Thiamin
0.54 mg Vitamin B₆
98 µg Folate
3.4 mg Manganese
1.6 mg Copper
158 mg Magnesium
346 mg Phosphorus
3.1 mg Zinc

[edit] Etymology and other names

The scientific name Juglans is from Latin jovis glans, "Jupiter's nut", and regia, "royal". Its common name, Persian walnut, indicates its origins in Persia in southwest Asia; 'walnut' derives from the Germanic wal- for "foreign", recognising that it is not a nut native to northern Europe.

Other names include Walnut (which does not distinguish the tree from other species of Juglans), Common Walnut and English Walnut, the latter name possibly because English sailors were prominent in Juglans regia nut distribution at one time.[1] In the Chinese and Korean languages, the edible, cultivated walnut is called 胡桃 (hú táo in Mandarin or 호두 hodu in Korean), which means literally "Hu peach," suggesting that the ancient Chinese associated the introduction of the tree into East Asia with the Hu barbarians of the regions north and northwest of China.

[edit] Folklore

In Skopelos, a Greek island in the Aegean Sea, local legend suggests that whoever plants a walnut tree will die as soon as the tree can "see" the sea. This has not been proven as fact, however it might take some time to find a local arborist willing to take on the job of planting a walnut tree. Most planting is done by field rats (subfamily Murinae).

In Flanders, the saying (in Dutch) goes "Boompje groot, plantertje dood", meaning "By the time the tree is big, the planter sure will be dead". The saying refers to the relatively slow growth rate of the tree.