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Juglans nigra var. oblonga

Interesting Facts

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Description

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Family Juglandaceae

Trees or rarely shrubs , deciduous, semievergreen, or evergreen , monoecious or rarely dioecious; bark tight (or exfoliating) . Branchlets with solid or chambered pith . Terminal buds subglobose or ovoid to oblong , naked or with scales . Stipules absent. Leaves alternate (or opposite), odd- or even-pinnate, sometimes trifoliolate , rarely simple ; leaflets with glandular , peltate scales, often resinous and aromatic , particularly conspicuous abaxially on young leaves and twigs , margin serrate or rarely entire. Inflorescences pendulous or sometimes erect , lateral or terminal, on reduced shoots arising on branchlets of previous year (old growth) or on current year’s growth (new growth), of several types: androgynous panicle with male, lateral spikes and female, central spike; androgynous panicle with male, mainly lateral spikes and female, central spike male at apex; cluster of male spikes and solitary female spike; or solitary male and female spikes. Flowers unisexual , anemophilous , rarely entomophilous. Male flowers subtended by an entire or 3-lobed bract; bracteoles 2 or absent; sepals 0-4, adnate to receptacle when present; stamens 3-40(-100), inserted on receptacle; filaments short to nearly absent, free or united at base ; anthers glabrous or pubescent , 2-loculed, dehiscing longitudinally. Female flowers with an entire or 3-lobed bracts; bracteoles 2 or 3 (or absent) ; sepals 0-4, adnate to ovary, free at apex; gynoecium of 2 carpels united into an inferior ovary , 1-loculed, but at base 2-4(-8) -loculed; style 1, short or elongate , rarely absent; stigmas 2, carinal or commissural , sometimes 4-lobed, plumose or fleshy ; ovule 1, orthotropous . Fruiting spike elongate, and pendulous or short and erect, rarely conelike. Fruit a drupelike nut, 2-4(-8) -chambered at base, with a dehiscent or indehiscent husk , or a 2- or 3-winged or disc-winged nutlet . Seed solitary, without endosperm. Cotyledons 4-lobed, much contorted. Germination hypogeal or epigeal. 2n = (28), 32, (64) .

Nine genera and 60 or more species: mostly in temperate and subtropical regions of the N hemisphere; seven genera (one endemic) and 20 species (seven endemic, one introduced ) in China.[1]

Genus Juglans

Shrubs or trees , 3-50 m. Bark light to dark gray or gray-brown, smooth or split into ridges or plates . Twigs purplish brown, terete , stout, sparsely to densely covered with glands and capitate-glandular hairs , sometimes also with scales or fasciculate hairs, early in season with multiradiate hairs; leaf scars triangular or 3-lobed, large; pith chambered . Bud scales valvate , densely hirsute . Leaves usually odd-, sometimes even-pinnate; petiole and rachis with indument as twigs. Leaflets 5-25, sessile or subsessile , often aromatic , uniform in size or median leaflets largest, (2.5-) 4.3-15(-17.5) × 0.8-6.5 cm; surfaces usually with nonglandular hairs (simple and/or fasciculate), glandular hairs, sessile glands, and/or scales, sometimes glabrous . Staminate catkins solitary from 2d-year twigs, sessile; stamens 7-50 per flower, glabrous or pilose . Pistillate flowers solitary or in terminal racemes . Fruits nuts enclosed in husks , not compressed ; husks thick, indehiscent; nuts tan, neither compressed nor angled , grooved , ridged , rugulose , or smooth; shells thick. Seeds sweet. x = 16.

Species 21: North America, Mexico, West Indies, Central America, South America, Eurasia .

Juglans is a very important source of edible nuts, dyes, and wood for cabinet work, furniture, and construction. Juglans regia Linnaeus, the walnut of commerce, is widely cultivated in California; it is easily distinguished from native species by its leaves with 5-11 broad, entire leaflets and nuts with thin rugulose shells, not grooved or ridged. Because of its sensitivity to native pathogens , J. regia is usually grown as stem-grafts on roots of native or hybrid walnuts (see discussion under J. hindsii). Occasional seedlings of J. regia have been reported from the vicinity of cultivated plants , but these seldom, if ever, live to maturity.

The growth form , bark, and fruit are important taxonomically in Juglans, but these usually are not available on herbarium specimens. As with many woody plants , the first one or two leaves of the season (i.e. , the lowermost leaves on the twig ) are sometimes atypical in structure, having broader, blunter leaflets. The fasciculate hairs on the veins normally have more rays than those on the blade . In addition to the types of hairs described below, small multiradiate hairs are found on the immature twigs, petioles, rachises, and midribs . They are usually gone when the leaf is fully expanded, but they may persist for a short time afterwards.[2]

Taxonomy

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Synonyms

Juglans nigra L. f. oblonga (Marshall) Fernald

Notes

Publishing author : Marshall .

Similar Species

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Members of the genus Juglans

ZipcodeZoo has pages for 82 species, subspecies, varieties, forms, and cultivars in this genus:

J. ailanthifolia (Japanese Walnut) · J. ailanthifolia var. cordiformis (Heartnut) · J. ailantifolia (Japanese Walnut) · J. australis (Nogal Criollo) · J. bixbyi (Bixby Walnut) · J. boliviana (Bolivian Walnut) · J. californica (Northern California Black Walnut) · J. californica S.Watson var. californica S.Watson (Southern California Black Walnut) · J. californica var. californica (California Walnut) · J. cinerea (Butternut) · J. cinerea 'Bountiful' (Butternut) · J. cinerea 'Loumis' (Butternut) · J. cordiformis 'Campbell Cw1' (Heartnut) · J. cordiformis 'Campbell Cw3' (Heartnut) · J. cordiformis 'Campbell Cww' (Heartnut) · J. cordiformis 'Frank' (Heartnut) · J. cordiformis 'Imshu' (Heartnut) · J. cordiformis 'Locket' (Heartnut) · J. cordiformis 'Marvel' (Heartnut) · J. cordiformis 'Mitchell Hybrid' (Heartnut) · J. cordiformis 'Rhodes' (Heartnut) · J. cordiformis 'Simcoe' (Heartnut) · J. cordiformis 'Stealth' (Heartnut) · J. cordiformis 'Wright' (Heartnut) · J. hindsii (Northern California Black Walnut) · J. illinoinensis (Pecan) · J. intermedia (Intermediate Walnut) · J. jamaicensis (Walnut) · J. major (Arizona Black Walnut) · J. mandshurica (Manchurian Walnut) · J. microcarpa (Little Walnut) · J. microcarpa var. microcarpa (Little Walnut) · J. microcarpa var. stewartii (Stewarts Little Walnut) · J. microcarpa var. stewartii (I.M.Johnst.) W.Manning (Stewart's Little Walnut) · J. microcarpa subsp. major (Little Walnut) · J. neotropica (Andean Walnut) · J. nigra (Black Walnut) · J. nigra 'Beineke 11' (Black Walnut 'beineke 11') · J. nigra 'Black Gem' (Black Walnut) · J. nigra 'Daniels' (Black Walnut) · J. nigra 'Emma Kay' (Black Walnut) · J. nigra 'Football 2' (Black Walnut) · J. nigra 'Krause' (Black Walnut) · J. nigra 'Kwik Krop' (Black Walnut) · J. nigra 'Laciniata' (Black Walnut) · J. nigra 'Lamb's Curly' (Black Walnut) · J. nigra 'Ridgeway' (Black Walnut) · J. nigra 'Rowher' (Black Walnut) · J. nigra 'Sauber 1' (Black Walnut) · J. nigra 'Schrieber' (Black Walnut) · J. nigra 'Sparrow' (Black Walnut) · J. nigra 'Surprise' (Black Walnut) · J. nigra 'Thomas Black' (Black Walnut) · J. nigra 'Thomas Myers' (Black Walnut) · J. regia (Carpathian Walnut) · J. regia var. Carpathian (Carpathian Walnut) · J. regia 'Allegheny' (Carpathian Walnut) · J. regia 'Bedco 1' (Carpathian Walnut) · J. regia 'Broadview' (Dwarf English Walnut) · J. regia 'Cascade' (Carpathian Walnut) · J. regia 'Champion' (Carpathian Walnut) · J. regia 'China-B' (Carpathian Walnut) · J. regia 'Coble #2' (Carpathian Walnut) · J. regia 'Colby' (Carpathian Walnut) · J. regia 'Greenhaven' (Carpathian Walnut) · J. regia 'Hansen' (Carpathian Walnut) · J. regia 'Kaiser' (Carpathian Walnut) · J. regia 'Ky Giant' (Carpathian Walnut) · J. regia 'Lake' (Carpathian Walnut) · J. regia 'Looking Glass' (Carpathian Walnut) · J. regia 'Mckinster' (Carpathian Walnut) · J. regia 'Northern Prize' (Carpathian Walnut) · J. regia 'Perry' (Carpathian Walnut) · J. regia 'Purpurea' (Carpathian Walnut) · J. regia 'Reda' (Carpathian Walnut) · J. regia 'S-1' (Carpathian Walnut) · J. regia 'Shiawassee' (Carpathian Walnut) · J. regia 'Somers' (Carpathian Walnut) · J. regia 'Utah Giant' (Carpathian Walnut) · J. × bixbyi (Bixby Walnut) · J. x intermedia (Intermediate Walnut) · J. 'Royal' (Walnut)

More Info

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Further Reading

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Notes

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Contributors

Identifiers

Footnotes

  1. Anmin Lu, Donald E. Stone & L. J. Grauke "Juglandaceae". in Flora of China Vol. 4 Page 277. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
  2. Alan T. Whittemore & Donald E. Stone "Juglans". in Flora of North America Vol. 3. Oxford University Press. Online at EFloras.org. [back]
Last Revised: 7/29/2012