Walnut, Black
Juglans nigra
Juglandaceae - Walnut

Description

Leaves: Alternate; once pinnately compound; 1' to 2' long; with 15 to 23 leaflets; terminal leaflet often missing; deciduous; leaflets 3" to 4" long, ovate-lanceolate, serrate margins, glabrous above, hairy beneath; light yellow-green; characteristic odor when crushed; rachis stout, usually hairy; leaflets often deciduous before the rachis/petiole, which can persist well into the winter and is a good identifying characteristic.

Twigs/buds: Twigs stout; light brown; with yellow-brown to brown, chambered or divided pith. Terminal bud short and blunt, larger than laterals, hairy; laterals much smaller, often with more than one at each leaf scar.

Flowers/fruit: Monoecious. Flowers small; male flowers on long catkins; female borne in groups of one to four. Fruit a 1-1/2" to 2" diameter nut; round; covered by a thick, glabrous, yellow-green, fleshy husk which becomes black and wrinkled; nut inside with rough, dark, very hard shell; sweet, oily, strong flavored nut meat within.

Bark: Dark brown to gray-black; broken pieces showing chocolate-brown; intertwining ridges forming a diamond pattern.

Wood: Important; sapwood white to light brown; heartwood chestnut-brown; growth rings distinct; semi- ring-porous; rays indistinct; hard; strong; used for lumber, fine furniture, veneer. This is our highest- valued hardwood, but it is not worth near as much in Utah as where it is native because of a lack of markets and the poorer quality of our trees for lumber and veneer.

General: Native to the eastern half of the U.S. but planted in Utah. It prefers rich, deep, well-drained bottom-land soil and under favorable conditions attains a large size. Very shade intolerant and adaptable to high soil pH. Fruit and/or plant part can be nuisances; use fruitless varieties if possible.

Landscape Use: Planted more in Utah in the past than now, so most trees you see will be large. Nice golden-yellow fall color if leaves are not diseased or drought stressed. Black walnut can be a nice, large shade tree, but be prepared for some mess from the nuts. Few cultivars exist. Quite a few large black walnut trees in northern Utah recently have experienced branch dieback or have even been killed by borers or an unknown disease. Zones 4-9.

Cultivar: 'Laciniata'.

Characteristics

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