A deciduous tree from 60 to 70, occasionally over 90 ft high, with glabrous branchlets. Leaves five-lobed, heart-shaped at the base, 4 to 7 in. wide and about three-fourths as long in adult trees (in young vigorous specimens they are considerably larger); bright green on both surfaces, glabrous except for a tuft of hairs in the axils of the veins; stalks exuding a milky sap when broken. Flowers greenish yellow, 1⁄3 in. diameter, produced in April before the leaves in erect, branching corymbs. Fruit pendulous, on stalks 2 to 3 in. long; keys 11⁄2 to 2 in. long, glabrous; the wings wide-spreading but not quite horizontal, 1⁄3 to 1⁄2 in. wide. Timber white, and fairly close and hard in grain.
Native of continental Europe, where it is widely spread in a wild state from Norway southwards; cultivated in England for centuries, but not a native. The Norway maple is one of the handsomest, hardiest, and most vigorous of introduced trees. Its leaves are thinner and brighter than those of common sycamore or of the plane, which they somewhat resemble. It is also more ornamental when in flower than most maples, and its leaves fade in autumn into various shades of red, brown, and yellow. It thrives in almost any soil, and even in the poor sandy soil at Kew grows rapidly. For forming a screen quickly it is preferable in many places to black Italian poplar, for although it does not grow so fast nor so big, it is a tree of better form and more interesting character. Easily increased by seeds, which are produced abundantly.
At Westonbirt there are five specimens of Norway maple over 70 ft in height and ranging from 8 to 101⁄2 ft in girth; the tallest of these, in Mitchell Drive, measures 90 × 8 ft (1966). At Beauport Park, Sussex, there is a fine tree with a wide spread of branches measuring 70 ft in height and 113⁄4 ft in girth at 3 ft (1965). Like the sycamore, the Norway maple attains a large size in Scotland. There are examples of 82 × 10 ft at Dawyck, Peebl. (1966), and 73 × 101⁄4 ft at Keillour Castle, Perths. Few large trees have produced more varieties under cultivation. More than twenty have been named, and of them the following are the more distinct:
cv. 'Aureo-marginatum'. – Leaves often three-lobed; lobes deep and long-pointed, margined with yellow. 'Heterophyllum Variegatum' is similar.
cv. 'Columnare'. – Leaves smaller and shallower-lobed than in the type; branches erect; habit columnar. Raised in the nursery of Simon-Louis at Plantières, near Metz, in 1855.
cv. 'Crimson King'. – Leaves deep crimson-purple throughout the summer; a seedling of 'Schwedleri', raised by Messrs Barbier of Orleans and put into commerce around 1946. 'Crimson King' is the name under which it was patented in the U.S.A See also 'Goldsworth Purple'.
cv. 'Cucullatum'. – Leaves long-stalked, fan-shaped, with seven or nine prominent veins instead of the usual five; base of leaf wedge-shaped or truncate, not heart-shaped. Of the same type as 'Laciniatum', but with the lobes not so long-pointed. Nicholson in Gard. Chron., Vol. 15, 1881, p. 564. There is an example at Kew measuring 50 × 43⁄4 ft, received from Van Volxem's nurseries in 1879. Another at Westonbirt, Glos., in Silkwood, probably planted at about the same time, measures 75 × 7 ft (1968).
cv. 'Dissectum'. – Leaves slit back to the stalk into three lobes, the basal pair often cut again almost as deeply, and all the lobes divided into secondary lobes with long drawn-out points. A small, bushy tree. Introduced by Knight and Perry from Belgium in 1845 but no tree that can with any certainty be ascribed to this clone has been traced. Von Schwerin (Gartenflora, Vol. 42, 1893, p. 586) adds that the young wood is brown, the unfolding leaves brownish, later dark green. Another tree with the same shape of leaf is 'Lorbergii', put into commerce by Van Houtte around 1881. This makes a taller tree to 60 or 70 ft and according to Von Schwerin (op. cit.) also differs from 'Dissectum' in its yellowish young wood and in its lighter green leaves, with the tips of the lobes standing out from the plane of the leaf. There is an example of 'Lorbergii' at Westonbirt, in Silkwood.
cv. 'Drummondii'. – Leaves very clearly variegated with white; the best of its class.
cv. 'Faasen's Black'. – Leaves dark purplish brown, glossy, folded upwards at the margins; young leaves not wrinkled. Autumn colour red. Raised at Herk-de-Stadt, Belgium, around 1936 and put into commerce by Faasen-Hekkens, Tegelen, Holland. For this information we are indebted to G. Krüssmann, Handbuch der Laubgehöolze. See also 'Goldsworth Purple'.
cv. 'Globosum'. – A dwarf form; head of foliage wide-spreading, dense, and mop-headed. Origin unknown; first described by Nicholson in Gard. Chron., Vol. 15, 1881, p. 564.
cv. 'Goldsworth Purple'. – Leaves light reddish brown and wrinkled when young, becoming deep, dull, blackish purple and remaining so until autumn. The original plant was presented to the Royal Horticultural Society's Garden at Wisley around 1936-7 by a lady in whose garden it had apparently arisen as a self-sown seedling but whose name was, unfortunately, not recorded. It was put into commerce by the Goldsworth Nurseries of Messrs Slocock around 1949. The parent tree still grows at Wisley in Seven Acres. For this information we are indebted to Mr Brian Mulligan, Director of the University of Washington Arboretum, who was assistant to the Director at Wisley from 1936 to 1941.
This clone is very similar to 'Faasen's Black' and 'Crimson King', both of continental origin. It has not been possible to find authentic specimens of either, but they are said to differ from 'Goldsworth Purple' in having the young leaves less brightly coloured and the mature ones somewhat glossier. 'Faasen's Black' has the young leaves scarcely wrinkled and gives red autumn colour.
cv. 'Laciniatum'. – A smaller and more twiggy tree than the type, of more erect, narrow habit. Leaves tapering and wedge-shaped at the base, the lobes ending in long, often curved, claw-like points. The oldest of named varieties, figured in an Austrian work in 1792, and known as the eagle's claw maple. The plant described appears to be part of a clone for which the epithet laciniatum has the sanction of long usage; var. laciniatum as understood by Loudon (Arb. et Frut. Brit., 1838, Vol. 1, p. 449 and fig. 121) is not the true eagle's claw maple.
cv. 'Nanum'. – Of dwarf, pyramidal shape. Nicholson in Gard. Chron., Vol. 15, 1881, p. 565. Also known as A. pyramidale nanum. There is a specimen at Kew received from Späth in 1900, measuring 23 × 13⁄4 ft.
cv. 'Palmatifidum'. – An ambiguous name, deriving from A. p. var. palmatifidum Tausch, which has been used for both 'Dissectum' and 'Lorbergii.'
cv. 'Reitenbachii'. – A less vigorous tree than 'Schwedleri'. Leaves reddish when young (red on the extension growths), later green but changing to dark red as autumn approaches; found on his estate by the German landowner Reitenbach and put into commerce by Van Houtte before 1874. According to Elwes it comes 'fairly true' from seed but the name should be used only for descendants of the original tree by vegetative propagation. The maple once grown on the Continent as A. platanoides rubrum is not the same as 'Reitenbachii.'
cv. 'Schwedleri'. – Leaves of a bright red when young, becoming green as they mature. A popular variety, beautiful in late April and May. Origin unknown; in cultivation 1869.
cv. 'Stollii'. – Leaves very large, up to 9 in. in diameter; lobes not deep, usually three and often entire Späth's nurseries, 1888.
cv. 'Walderseei'. – Leaves densely speckled with white dots, so as to give a delicate grey appearance; lobing rather irregular. Put into commerce by Späth's nurseries, 1904.
From the Supplement (Vol. V)
specimens: West Dean Arboretum, Sussex, 98 × 9 ft (1980); Boldre Church, near Lymington, Hants, 56 × 91⁄2 ft, a fine dome (1981); Westonbirt, Glos., pl. 1876, 88 × 101⁄4 ft (1982), and three others of about the same size; Altyre, Moray, 72 × 111⁄2 ft (1981); Castle Fraser, Aberd., 85 × 121⁄4 ft (1983).
cv. 'Crimson King'. – An error, corrected in the reprints, is that this clone was not raised by Messrs Barbier, only distributed by them.
cv. 'Cucullatum'. - specimens: Kew, pl. 1879, 50 × 43⁄4 ft (1979); Kensington Gardens, London, 70 × 73⁄4 ft and 72 × 71⁄4 ft (1978); Osterley Park, London, 70 × 71⁄2 ft (1982); Alexandra Park, London, pl. 1880, 60 × 71⁄4 ft (1983); Westonbirt, Glos., 92 × 8 ft and two others slightly smaller (1982); Edinburgh Botanic Garden, 85 × 71⁄2 ft (1985).
Mention was made on page 225 of 'Olmsted'. Other habit selections of the Norway maple have been made in the USA and are surveyed in Dendroflora No. 19, pp. 47-9 (1982, in Dutch, with drawings indicating habit). Most of these can be seen in the Hillier Arboretum, Ampfield, Hants.
† cv. 'Royal Red'. – Raised in the USA, this is considered by some to be the best of the purple-leaved Norway maples, the leaves of a redder shade than in any of the others.