ACER (from acer, hard or sharp; wood is extremely hard, and was formerly much used for making pikes and lances). Maple. ORD. Sapindaceae. A genus comprised, for the most part, of handsome hardy deciduous shrubs, or trees, adapted for forming shrubberies, plantations, &c. Flowers greenish, except where mentioned. ACER Pseudo-platanus is one of our most useful forest trees. Several of the species produce very useful timber, sugar is one of the constituent parts of the sap of all of them, and is obtained in large quantities from ACER saccharinum, in North AmericACER They all prefer a some-what sheltered position. The most satisfactory soil is one free, deep, loamy, and well drained; the latter is especially desirable with some of the Japanese varieties. The varieties of ACER japonicum, and palmatum are well worth growing in pots for conservatory decoration. Propagation: By seeds, sown either in autumn or spring, covering them not more than a 1/4in. deep; the common varieties may be sown outside, while the rarer ones should be sown in a frame. By layers, and by grafting; the latter method is adopted with many of the rarer species and varieties, especially the variegated kinds; they are also readily increased by budding in summer. ACER austriacum (Austrian). Synonymous with ACER campestre austriacum. ACER campestre (field)* Common Maple fl. on erect racemes. May. fr. wings of fruit much divaricated. l. small, cordate, with five-toothed lobes. h. 20ft. Britain. A small tree with rough bark, full of deep fissures; wood often beautifully veined, when it is highly valued. ACER campestre austriacum (Austrian).* fl. much larger than those of the species. fr. smooth. Lobes of leaves somewhat acuminated. SYN. ACER austriacum. ACER campestre collinum (hill-loving).* fl. smaller. fr. smooth. Lobes of leaves obtuse. France. ACER campestre hebecarpum (downy-fruited).* fr. clothed with velvety pubescence. ACER campestre laevigatum (smooth-leaved). l. very smooth and shining. ACER campestre nanum (dwarf). Dwarf habit. ACER campestre tauricum (Taurian).* l. larger and less divided than in the species. ACER campestre variegatum (variegated).* l. beautifully variegated with blotches and stripes of white or whitish yellow; very distinct. ACER circinatum (circinate).* fl. deep red, umbellate. April. l. seven to nine-lobed, serrulated. h. 5ft. to 6ft. North West America, 1827. A very beautiful species, having pendulous branches clothed with leaves, which change into a bright scarlet colour in the autumn. ACER colchicum tricolor (Colchican, three-coloured). A synonym of A. pictum tricolor. ACER creticum (Cretan). fl. on few-flowered erect corymbs. May. fr. smooth, with the wings hardly diverging. l. cuneated at the base, acutely three-lobed at the top. h. 4ft. Levant, 1752. Nearly evergreen. ACER dasycarpum (thick-fruited).* fl. conglomerate, on short pedicels, apetalous. April. l. truncate at the base, palmately five-lobed, with blunt recesses, and unequally and deeply-toothed lobes. h. 40ft. North America, 1725. SYNS. ACER eriocarpon, ACER tomentosum, ACER glaucum, and ACER virginianum. ACER Douglasii (Douglas). Synonymous with ACER glabrum. ACER eriocarpon (hairy-fruited). Synonymous with ACER dasycarpum. ACER Ginnala (Ginnalian).* fl. on compound, crowded, erect racemes. Amur River. This is generally classed as a variety of ACER tartaricum, but its habit is much more graceful, and in this form the leaves are prettily cut and lobed, whilst the leafstalks and midrib are more deeply coloured. ACER glabrum (smooth).* fl. corymbose, on short two-leaved branchlets, greenish-yellow. June. l. roundish-cordate, deeply three to five-lobed, or partite; the lobes bi-serrate, of a light green. h. 15ft. to 30ft. North West America. SYNS. ACER Douglasii, ACER tripartitum. ACER glaucum (glaucous). Synonymous with ACER dasycarpum. ACER Heldreichii (Heldreich's). fl. in small, terminal panicles, which are shorter than the leaves. l. small, palmately five-lobed; lobes obtusely dentate, acute, the middle one cuneately tapering to its base. Greece. (G. C. n. s., xv., p. 141; R. G. 1185.) ACER heterophyllum (various-leaved).* fl. corymbose. May. l. small, ovate, entire, and three-lobed, slightly serrated, smooth, h. 4ft. Levant, 1759. An evergreen. SYN. ACER sempervirens. ACER ibericum (Iberian). fl. corymbose. May. l. bluntly threelobed; lobes with one or two teeth, lateral ones marked with the middle nerve to the insertion of the petiole. h. 20ft. Iberia, 1826. ACER insigne (remarkable).* fl. green, 1/4in. in diameter; panicles pyramidal, terminal, 3in. to 4in. long, appearing with the leaves. May. l. 5in. to 6in. in diameter, rounded-reniform, palmately divided to the middle into five to seven oblong, acute, coarsely and obtusely serrated lobes, glabrous above, more or less tomentose beneath. Persia. The latest of all the Maples to come into leaf. (B. M. 6697.) SYN. ACER velutinum. ACER japonicum (Japanese).* fl. deep purplish-red, large. April. l. many-lobed, in early spring very light green. h. 20ft. Japan, 1863. The varieties of this species, although not well fixed in many cases, rank amongst the most handsome of the deciduous small shrubs grown, but often change in character as they attain any considerable size. Plants from 1 1/2ft. to 3ft. high are very useful in cool conservatories, and in the highly kept grounds surrounding the house. ACER laurifolium (laurel-leaved). Synonymous with ACER oblongum. ACER Lobelii (Lobel's). l. very slightly heart-shaped, irregularly toothed, five-lobed; lobes more or less abruptly pointed. ACER macrophyllum (large-leaved).* fl. on erect, compound, racemes. May. l. digitately five-palmate, with roundish recesses; lobes somewhat three-lobed. h. 60ft. Northern California, 1812. ACER monspessulanum (Montpellier).* fl. on few-flowered corymbs, erect. May. l. cordate, three-lobed; lobes almost or quite entire, equal. h. 10ft. to 20ft. South Europe, 1739. ACER montanum (mountain). fl. on compound, erect racemes, May. l. cordate, three or slightly five-lobed, unequally and coarsely serrated. h. 18ft. Canada, 1750. SYN. ACER spicatum. ACER Negundo. See Negundo aceroides. ACER oblongum (oblong). fl. on compound racemes, pale yellow. February. l. oblong-lanceolate, acuminated, quite entire. h. 20ft. Nepaul, 1824. SYN. ACER laurifolium. ACER obtusifolium (obtuse-leaved). fl. drooping, corymbose. May. l. rounded, bluntly three-lobed, crenately serrulate, about the length of the petioles. h. 15ft. Crete. ACER Opalus (Opalus). A synonym of ACER opulifolium. ACER opulifolium (Guelder-rose-leaved).* fl. on nearly sessile corymbs. May. Ovaries and fruit smooth. l. cordate, five-lobed; lobes obtuse, bluntly and coarsely toothed. h. 8ft. France, 1823. SYN. ACER Opalus. ACER opulifolium obtusatum (bluntish).* A larger, strong growing, round-headed tree, with dark green leaves, which are covered with a whitish or rusty tomentum on the under surface. ACER palmatum (palmate-leaved).* fl. on five to seven-flowered umbels. May. l. palmately divided into five to seven lobes beyond the middle; lobes oblong, acuminated, serrated. h. 20ft. Japan, 1820. ACER palmatum atropurpureum (dark purple).* A vigorous handsome plant, with bold dark purple foliage. Japan. ACER palmatum crispum (crispy or waved).* l. green, with red stalked, convoluted edges. Japan, 1871. Very distinct, and like a miniature Lombardy poplar in habit of growth. ACER palmatum dissectum (finely-divided).* fl. red, on terminal-stalked racemes, five to six-flowered. May. l. nine to ten parted; lobes oblong, acuminated, deeply serrated. h. 30ft. Japan, 1845. ACER palmatum ornatum (beautiful).* Very ornamental, having finely cut deep red leaves, with lighter midribs. Japan, 1871. This variety is also known as dissectum. ACER palmatum palmatifidum (palmatifid).* l. very finely palmately divided, the lobes cut down quite to the midrib, of a beautiful light green colour. 1875. ACER palmatum reticulatum (netted).* l. palmately seven-lobed; lobes unequal, sharply serrate, emerald green, with dark green veins. Japan, 1875. A very elegant variety, with slender branches. ACER palmatum roseo-marginatum (rose-margined).* l. freely divided, the lobes deeply cut, light green, margined with rose. Japan, 1874. A very distinct and charming variety. ACER palmatum sanguineum (blood-red).* l. deeply five-lobed, the lobes serrated, of a deep reddish-crimson colour, much brighter than the variety atropurpureum. 1874. This presents a very striking contrast to the last. ACER palmatum septemlobum (seven-lobed).* fl. purplish, on numerous flowered umbels. Spring. l. varying much, from palmately five-lobed, with toothed undivided lobes, to deeply seven to nine-lobed, with more or less finely cut divisions. Japan, 1864. There are numerous beautiful forms of this variety. There are many varieties of this much varying species, but we have only mentioned those best known; many are only known by their native names, and there is some doubt as to their distinctive characteristics. They are all extremely handsome. ACER pennsylvanicum (Pennsylvanian).* fl. in long drooping, simple racemes. May. l. cordate, three-lobed, acuminated, finely and acutely serrated. h. 20ft. Trunk elegantly striped with white lines. North America, 1755. SYN. ACER striatum. ACER pictum (painted).* fl. corymbose, stalked. l. five to seven-lobed; lobes triangular or oblong, entire, acuminated. h. 15ft. to 20ft. Temperate Asia, 1840. ACER pictum connivens (converging), ACER pictum marmoratum (spotted), ACER pictum rubrum (red), and ACER pictum variegatum (variegated), are varieties differing principally in the colouring of the leaves. All are very desirable. ACER pictum tricolor (three-coloured). l., young ones of a bright violaceous-red, irregularly shading off here and there into all tints of dark red or crimson to creamy-white. 1886. Garden variety. SYN. A. colchicum tricolor. ACER platanoides (plane-like).* The Norway Maple. fl. on nearly erect stalked corymbs. May, June. l. cordate, smooth, five-lobed; lobes acuminated, with a few coarse acute teeth. h. 50ft. Europe, 1683. A very ornamental hardy tree, growing with great rapidity when young. It prefers a deep, well-drained soil. ACER platanoides aureo-variegatum (golden-variegated).* l. variegated with yellow. Europe, 1383. This, to retain the variegation, requires to be propagated by budding or grafting. The same remarks are equally applicable to the other varieties. ACER platanoides compactum (compact). An ornamental variety, producing a compact, round head. 1886. ACER platanoides integrilobum (entire-lobed). This only differs from the type in having the lobes of the leaf entire. (R. G. 1887, p. 431, f. 107-8.) ACER platanoides laciniatum (cut-leaved).* l. deeply and variously cut, green and yellow. ACER platanoidesReichenbachii (Reichenbach's). l. large, changing in the autumn to a deep crimson-red, varying to yellow and brown. ACER platanoides Schwedleri (Schwedler's).* l. very large, deep bronzy-red. A vigorous grower, and most effective. ACER platanoides undulatum (wavy). l. bullate, with very wavy, crisped margins. A curious and interesting variety. ACER platanoides variegatum (variegated).* l. variegated with white. There are several other varieties, but of less importance than the foregoing. ACER velutinum (velvety). A synonym of ACER insigne. ACER Pseudo-platanus (Mock-plane tree).* Sycamore. fl. on rather compound pendulous racemes. May. l. cordate, with five acuminated unequally-toothed lobes. h. 30ft. to 60ft. Europe. There are few deciduous trees so well adapted for standing singly in rough exposed situations. A deep, soft, dry soil is most suitable for it, but it will grow in soils of very opposite qualities. ACER Pseudo-platanus albo variegata (white-variegated).* A very beautiful form, in spring especially. l. white and green. ACER Pseudo-platanus flavo variegata (yellow-variegated). l. variegated with yellow. ACER Pseudo-platanus longifolia (long-leaved).* l. more deeply cut, and the petioles much longer than in the species. ACER Pseudo-platanus purpureum (purple).* l. purple underneath. The tree, when slightly ruffled by the wind, alternately appearing clothed in purple and pale green. Numerous other varieties of more or less excellence are grown. ACER rubrum (red).* Scarlet Maple. fl. scarlet, handsome, conglomerate, corymbose. l. cordate at the base, deeply and unequally toothed, palmately five-lobed, with acute recesses. Branches and fruit also scarlet. h. 20ft. Canada, 1656. A variety with leaves splashed with yellow is rare. An excellent species, thriving well in damp, swampy situations, and is commonly increased by layers. ACER rufinerve (red-nerved).* "The leaves vary both in size and outline, from 2 1/2in. to 4in. each way; three to five-lobed, with irregularly toothed margins, glabrous above, but with reddish hairs along the nerves beneath. The young branches are conspicuous on account of the bluish-grey glaucescence with which they are covered." ACER rufinerve albo-limbatum (white-margined)* differs only from the species in having a very distinct white margin-not always constant. Japan, 1869. ACER saccharinum (Sugar Maple).* fl. yellow, on drooping corymbs, on short peduncles; pedicels pilose. April. l. cordate, smooth, palmately five-lobed; lobes accuminated, sinuately toothed. h. 40ft. N. America, 1735. ACER saccharinum nigrum (blackish).* fl. on sessile corymbs, nodding. April, May. l. cordate, with the recess closed; palmately five-lobed. h. 40ft. North America, 1812. ACER Semenovi (Semenov's).* A slender and graceful species, with leaves closely resembling those of ACER Ginnala, but smaller. Turkestan, 1879. ACER sempervirens (evergreen). Synonymous with ACER heterophyllum. ACER spicatum (spiked). Synonymous with ACER montanum. ACER striatum (striated). Synonymous with ACER pennsylvanicum. ACER tartaricum (Tartarian).* fl. white, on crowded, erect, compound racemes. May. l. more or less cordate, acuminated, serrated, with obsolete lobes. h. 20ft. 1759. This species is one of the first to expand its leaves in spring. ACER tomentosum (tomentose). Synonymous with ACER dasycarpum. ACER tripartitum (three-parted). Synonymous with ACER glabrum. ACER Van Volxemii (Van Volxem's). fl. not known in England. l. palmately three to five-lobed, very large, light green above, silvery and quite glabrous beneath. Caucasus, 1877. Distinct and fine. ACER villosum (hairy). fl. fragrant, on lateral racemes. April. Buds, fruit, and young leaves, silky, villous. l. cordate, five-lobed, villous beneath as well as the petioles; lobes ovate acute. h. 50ft. Himalaya, at high elevations. Not hardy. ACER virginianum (Virginian). Synonymous with ACER dasycarpum.