A North American walnut treasured for its dark, richly figured timber and its tough-shelled, strongly flavoured nuts.
Where it grows
Black walnut grows in deep, moist soils from southern Ontario and Vermont west to South Dakota and south to northern Florida and east Texas, with its commercial centre in the Mississippi and Ohio River valleys. It rarely forms pure stands but is a high-value scattered tree of farm woodlots.
How to recognise it
The pinnate leaves carry 15 to 23 lance-shaped serrated leaflets and release a strong distinctive scent when crushed. The bark is deeply furrowed and dark grey-black. The fruit is a tennis-ball-sized green husk that turns black with a fleshy, deeply pungent rind enclosing a thick, ridged, dark brown nut.
Uses
Black walnut heartwood is famously dark chocolate-brown with purple highlights, dimensionally stable, and easy to work — the premium American cabinet timber, used in fine furniture, gunstocks, and high-end veneers. The husks yield a famously persistent brown-black dye. The nuts are bold-flavoured and prized in ice cream and baking, especially across the Midwest.
Allelopathy
Like English walnut, black walnut roots release juglone, which suppresses sensitive plants in the soil within the tree’s root zone — a key consideration in mixed-species plantings.