A deciduous tree up to 70 or 80 ft high; young shoots warted, not downy; winter-buds downy towards the points, up to 1⁄4 in. long. Leaves 3 to 6 in. long, 21⁄2 to 41⁄2 in. wide (in young trees as much as 6 in. wide), obovate or oval, tapered at the base, deeply seven- sometimes nine-lobed, the lobes oblong or triangular, coarsely and unequally toothed at the apex, dark green above, paler beneath, both sides lustrous and glabrous, except that there are sometimes tufts of brownish down in the vein-axils beneath; stalk 11⁄2 to 21⁄2 in. long, glabrous, yellow. Acorns 1⁄2 to 1 in. long, two-thirds as wide, one-third to one-half enclosed in a deep, thin-edged cup.
Native of eastern N. America; introduced about the end of the 17th century. The true scarlet oak retains its leaves until November or December, and for the last six or eight weeks they are of a brilliant red, and make one of the richest of autumnal effects. But early frost may cause the leaves to wither before they have coloured, and trees raised from seed cannot be relied on always to give the autumn colouring expected of this species.
In its native country the scarlet oak does not attain such a large ultimate size as the red oak (Q. rubra) and reaches maturity at an earlier age. It is less demanding in its soil requirements, and is commonly found on dry, rather acid soils. Early this century, Elwes and Henry remarked on the scarcity of the scarlet oak in Britain and knew of no better tree than one at Arley Castle, measuring 78 × 61⁄4 ft (1904). The following specimens, recorded in recent years, are probably all less than a century old: Kew, by Main Gate, 56 × 61⁄4 ft (1967), near Oak collection, 60 × 61⁄4 ft (1965); Syon House, London, 70 × 81⁄4 ft (1968); Osterley Park, London, four trees 65 to 70 ft high, 53⁄4 to 63⁄4 ft in girth (1965); Windsor Great Park, China Island, 75 × 9 ft (1964); Frensham Hall, nr Haslemere, Surrey, pl. 1905, 80 × 61⁄4 ft (1968); Nymans, Sussex.pl. 1902, 80 × 71⁄4 ft (1968); Sheffield Park, Sussex, four trees 70 to 75 ft high, 7 to 81⁄4 ft in girth (1968); Grayswood Hill, Surrey, 80 × 81⁄4 ft (1971); Westonbirt, Glos., opposite Wigmore Bottom, 80 × 53⁄4 ft (1967), Circular Drive, 78 × 81⁄4 ft (1969), three in The Downs pl. 1926, 57 to 65 ft high, 5 to 6 ft in girth; Saltram House, Devon, 77 × 71⁄4 ft (1970); Killerton, Devon, in Park 55 × 7 ft (1970); Sandon Park, Staffs., 74 × 93⁄4 ft (1969).
cv. ‘Splendens’ (‘Knap Hill’) – A selection with unusually brilliant autumn colouring, introduced by the Knap Hill Nursery at the end of the last century. Award of Garden Merit 1927. A specimen at Kew, grafted at 1 ft, is 65 × 71⁄4 ft (1969).