A deciduous tree 70 to 100 ft high, forming a dense head of slender branches pendulous at the ends; bark broken into flat, scaly ridges; young shoots not downy, warted; winter-buds about 1⁄8 in. long. Leaves 3 to 6 in. long, nearly as wide, obovate, tapered or cut nearly straight across at the base, five- or seven-lobed, the lobes reaching three-quarters of the way to the midrib, oblong or triangular, unequally toothed near the apex, both surfaces are glossy green and glabrous, except that, in the vein-axils beneath, there are large conspicuous tufts of greyish down; stalk very slender, up to 2 in. long. Acorn about 1⁄2 in. long and broad, flattish at the base, where it is enclosed by a shallow saucer-shaped cup.
Native of the eastern United States from New England to northern N. Carolina, westward to western Kansas and Oklahoma; introduced to England in 1800. It occasionally bears crops of acorns, which require two seasons to mature. It is one of the very best growers among American oaks cultivated in this country, and is very elegant in its slender branches, especially whilst young or of the middle size. The leaves often turn deep scarlet in autumn, but I do not think it is so effective and reliable in this respect as Q. coccinea; on the dry soil at Kew it is, at any rate, much inferior. It is frequently confused with Q. coccinea, but Q. palustris is distinguished by its more densely branched graceful head, by the invariable and conspicuous tufts of down beneath the leaf, by the shallower acorn-cup, and by the glabrous winter-buds. From Q. rubra it differs in the more deeply divided leaves, polished green on both sides.
The largest of the following specimens are well up to the average size of mature wild trees: Kew, near the Victoria Gate, 84 × 81⁄2 ft (1963), Oak collection, 72 × 73⁄4 ft (1972); Syon Park, London, 78 × 8 ft (1967); Marble Hill, Twickenham, London, 80 × 81⁄2 ft (1968); Mill Hill School, London, 75 × 91⁄2 ft (1964); Godinton Park, Kent, two very fine trees measuring 62 × 73⁄4 ft and 64 × 9 ft (1965); Canford, Dorset, a tree dead at the top, 80 × 8 ft in 1906, now 68 × 121⁄2 ft (1965).
Q. palustris is a quick-growing tree in a deep, moist, light soil, but not long-lived.
Q. × richteri Baenitz – A hybrid between Q. palustris and Q. rubra, described from cultivated trees but also reported from the wild. Mme Camus, who saw only foliage specimens, considered it to be indistinguishable from Q. coccinea in its leaves. But the acorn-cup is shallower than in that species.
Q. ellipsoidalis E. J. Hill Q. coccinea var. microcarpa Vasey Northern Pin Oak. – Although classified by botanists with Q. coccinea this species resembles Q. palustris in habit and, as in both these species, the leaves are glabrous beneath except for axillary tufts. From Q. coccinea it differs in the smaller buds (only 1⁄8 in. long) and in having almost sessile fruits with the cups gradually tapered at the base. From Q. palustris it differs in the deeper cup of the fruit, which encloses one-third to one-half of the acorn. It occurs west and south of the Great Lakes, in dry soil. There is a specimen in the Edinburgh Botanic Garden, measuring 40 × 23⁄4 ft (1967).