A deciduous tree 30 to 40 ft high, with smooth blue-white young shoots. Leaves 21⁄2 to 5 in. long, three-lobed or obscurely five-lobed, truncate or heart-shaped at the base; terminal lobe triangular, larger than the side ones, margins finely and irregularly toothed; upper surface dark green, glabrous; lower one paler, with reddish down along the veins, conspicuous when the leaf is young, but largely falling away by autumn. Flowers in erect racemes about 3 in. long, each one on a stalk 1⁄8 to 1⁄4 in. long; the common stalk covered with reddish down. Keys 1⁄2 to 3⁄4 in. long, the nutlets at first covered with reddish down, afterwards glabrous; wings diverging at from 90° to 120°.
Native of Japan; introduced for Messrs Veitch's nurseries by Charles Maries about 1879. It is nearly allied to A. pensylvanicum, resembling it somewhat in shape of leaf, and in the handsome markings of the branches; but differing in the glaucous young shoots, and in the more conspicuous reddish down beneath the leaves. The glaucous young shoots are also a good field character by which to distinguish A. rufinerve from A. capillipes (q.v. for further marks of difference) and from A. grosseri var. hersii. The foliage sometimes dies off a rich crimson.
This attractive maple thrives very well in cultivation. There are specimens of 40 ft high or near at Kew and at Hergest Croft, Heref.; Westonbirt, Glos.; Coles, Privett, Hants; and in the Glasnevin Botanic Garden, Dublin.
f. albolimbatum (Hook. f.) Schwer. – A beautiful maple, whose leaves have a broad margin (or sometimes the whole surface) entirely covered with spots of white. It was introduced by Standish of Ascot, some years before the type, and was first exhibited by him in 1869. Bot. Mag., t. 5793. It is propagated by seed and very variable in its leaf-marking. There is a fine group in the Winkworth Arboretum, Godalming, Surrey.