|Juglans regia subsp. var.|
The English Walnut (Juglans regia), also known as Common Walnut or Persian Walnut, is a species of walnut that is native in a region stretching from the Balkans (in southeast Europe) eastward — all the way to the Himalayas and southwest China. The largest forests are in Kyrgyzstan, where English Walnut trees occur in extensive, nearly pure walnut forests at 1,000–2,000 m altitude (Hemery 1998)—notably at Arslanbob in Jalal-Abad Province.
English Walnut 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.
Cultivation and uses
Persian walnut is originaly from Iran where it still can be found in nature and also is widely cultivated. The English Walnut was introduced into western and northern Europe very early, by Roman times or earlier, and to the Americas by the 17th century. 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.
|Standard Cyclopedia of Horticulture|
Juglans regia, linn. Persian or English Walnut. Round-headed tree, to 70 ft.: lfts. 5-13, oblong or oblong-ovate, acute or acuminate, almost glabrous, bright green, 2-5 in. long: fr. almost globular, green; nut usually oval, reticulate and rather smooth, rather thin-shelled. S. E. Eu. Himalayas, China. U.S. Many varieties are cult, as fr. trees, for which see Walnut. var. sinensis, DC. (J. sinensis, Dode). Lfts. usually 5, larger, pubescent on the veins below: nut globose-ovoid, very rugose. China, Japan. SOf the ornamental varieties the most distinct and decorative is var. laciniata, Loud. (var. filicifolia, Hort. var. asplenifolia, Hort.), with narrow, pinnately cut lfts.; very effective as a single specimen on the lawn; remains usually shrubby. M.D.G. 1908:617. var. monophylla, DC., has the lvs. simple or 3-foliolate. var. pendula, Kirchn., has pendulous branches. Var. fSrtilis, Kirchn. (var. frulicosa, Dipp. var. prapar- turiens, hort.), is a shrubby variety producing rather small, thin-shelled nuts on very young plants. Var. Bartheriana, Carr. (var. elongata, Hort.). Nut elongated, narrow- oblong. var. corcyrensis, Sprenger. Lvs. large, to 2 ft. long; lfts. 9, the lowest pair very small, the upper pairs broadly ovate, about 8 in. long and 5 in. broad: nut rather thick-shelled. J. Duclouxiana, Dode, from the Himalayas and W.China with more elliptic and more acuminate lfts. and nuts with thin fragile shell, is probably only a variety of J. regia.
Pests and diseases
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963