A tree 50 to 60, rarely 100 ft high, usually forming a wide-spreading head of branches; young wood covered with a dense, rusty brown, clammy felt, which partly falls away by the end of the season. Leaves 10 to 20 in. long, composed of seven to nineteen leaflets, which are 2 to 5 in. long, 3⁄4 to 21⁄4 in. wide, oblong lance-shaped, taper-pointed, obliquely rounded at the base, finely and regularly toothed, upper surface at first hairy, especially on the midrib; lower surface covered with soft, star-shaped hairs; common-stalk thickly furnished with gland-tipped, sticky hairs. Male flowers in catkins 2 to 4 in. long. Fruits three to five in a drooping cluster, each tapering to a point at the top, rounded at the base, 11⁄2 to 21⁄2 in. long, covered with sticky hairs; nut 1 to 11⁄2 in. long, with a short point; kernel sweet, oily.
Native of eastern N. America; introduced early in the 17th century. Although so long cultivated, this tree is comparatively rare in Britain, and is evidently not so well adapted for our climate as the black walnut, rarely bearing fruit. As a small tree it is quite handsome, but grows slowly. From J. nigra it differs in its pointed, more numerous fruits, its more downy leaves, and by a transverse tuft of down between the scar left by each fallen leaf and the bud above it.
There are two specimens of J. cinerea at Westonbirt, Glos., one in the Acer glade of the Arboretum, measuring 65 × 31⁄2 ft (1967) and another in the grounds of Westonbirt School, pl. 1928, now 55 × 21⁄2 ft (1967). Both are graceful straight trees. Two recorded in Scotland are: Edinburgh Botanic Garden, 47 × 31⁄2 ft (1967), and Glendoick, Perths., 46 × 41⁄4 × 3 ft (1970).