A deciduous tree, occasionally over 100 ft high in America, with a trunk up to 13 ft in girth; and over 70 ft high in England, forming a rounded head of branches; bark greyish; branchlets glabrous, except when quite young. Leaves three- or five-lobed (the lobes pointed and somewhat triangular, the middle one usually the longest), from 2 to 5 in. wide, and often longer than broad, coarsely and unevenly toothed; upper surface dark green, glabrous, lower one blue-white and more or less downy, especially along the veins. Flowers appearing in March and early April in dense clusters before the leaves, at the joints of the previous year’s wood, or on short spurs of still older wood, rich red, each flower on a reddish stalk at first quite short, but lengthening as the flower and fruit develop. Fruits on slender drooping stalks 2 to 3 in. long; wings about 3⁄4 in. long, 1⁄4 in. wide, dark dull red spreading at about 60°.
Native of eastern N. America, and already in cultivation in England by the middle of the seventeenth century. It is a handsome and fairly common tree. When the first edition of this work was published the largest in the country grew at Bagshot Park, Surrey, which measured 80 × 91⁄2 ft (1907); the tallest there now is 65 × 101⁄2 ft (1960). At Westonbirt there is a specimen of 73 × 43⁄4 ft in Willesley Drive and two others in the collection approaching that size. At Wakehurst Place it is 65 × 61⁄2 ft (1966) and at Kew 52 × 53⁄4 ft (1960). The red maple is represented in the R.H.S. Gardens, Wisley, by an example 45 ft high, near the lake.
There is a considerable resemblance between this tree and A. saccharinum, and they are frequently confused. A. rubrum, however, is more compact and of slower growth; the leaves are not so much or so deeply cut, the down beneath them more fluffy, and the fruits are less than half as large. In the United States this maple produces most beautiful colour effects in autumn, the leaves turning scarlet and yellow. In this country it is not so good, but sometimes the leaves change to bright yellow, or dark brownish red, or occasionally red. It should be planted in a moist position.
cv. ‘Columnare’. – A pyramidal variety figured in Garden and Forest, 1894, p. 65, growing in private grounds at Flushing, New York, which was then 80 ft high. The figure is erroneously described as a form of sugar maple.
var. drummondii (Hook. & Arn.) Sarg. A. drummondii Hook & Arn. – Differs in the downy character of the young shoots, leaf-stalks, and under-surface of the leaves. Fruit and flowers bright scarlet, the former larger than in ordinary A. rubrum. Native of Arkansas, Texas, and Louisiana.
cv. ‘Sanguineum’. – The original tree of this variety grew at the Jardin des Plantes, Paris. Its leaves are glaucous green beneath, somewhat more downy than in the type, the flowers brilliant red. The leaves are said to turn a rich red in the autumn but at Kew, where there is an example 55 ft high, they colour no better than in the type.
cv. ‘Schlesingeri’. – A clone selected in the United States for its brilliant autumn colour. It was found by Prof. Sargent in the grounds of a Mr Schlesinger and put into commerce in Europe by Späth’s nurseries in 1888.
A. pycnanthum K. Koch A. rubrum var. pycnanthum (K. Koch) Mak. – A rare tree, found in wet places in the mountains of the northern part of the main island of Japan. It is a close ally of the American red maple, differing in the shallowly three-lobed leaves, which are glaucous and glabrous beneath; and in the almost erect fruit-wings. Probably not in cultivation in Britain.