The species in cultivation are :—
1. Liquidambar styracifilua, Linnæus. North America.
Shoots glabrous. Leaves large, usually five-lobed, only occasionally lobulate in margin ; under surface glabrous, except for dense tufts of pubescence in the axils of the main nerves at the base, and occasional minute tufts at the junctions of the lateral and main nerves.
2. Liquidambar orientalis, Miller. Asia Minor.
Shoots glabrous. Leaves small, five-lobed, margin with large lobules; under surface quite glabrous.
3. Liquidambar formosana, Hance. China, Formosa, Tonking.
Shoots pilose. Leaves large, usually three-lobed ; under surface pilose, without conspicuous axil-tufts.
LIQUIDAMBAR STYRACIFLUA, Sweet Gum
- Liquidambar styracifiua, Linneus, Sp. Pl. 999 (1753); Loudon, Arb. et Frut. Brit. iv. 2049 (1838); Oliver, in Hooker, Icon, Plant. xi. 13 (1867); Sargent, Silva N. Amer. v. to. t. 199
(1893), and Trees N. Amer. 340 (1905).
- Liquidambar macrophylla, Oersted, Am. Cent. xvi. t. 10 (1863).
A tree, attaining in America 160 feet in height and 17 feet in girth. Bark deeply and longitudinally fissured, with broad ridges covered by thick corky scales.
Young shoots green, glabrous. Leaves (Plate 199, Fig. 7) large, averaging 6 inches broad and 5 inches long, variable in form, cordate or almost truncate at the base, five-nerved, palmately and deeply cut into five oblong-triangular acuminate lobes, the terminal lobe largest, the basal lobes smallest, rarely lobulate ; serrations shallow, non-ciliate ; upper surface dark green, shining, glabrous ; lower surface light green, shining, glabrous except for dense tufts of pubescence in the axils of the nerves at the base and occasional minute tufts at the junctions of the lateral and main nerves. Petiole glabrous, slightly grooved on its upper side, dilated at the base, near which are two scars indicating where the lanceolate stipules have fallen off in early summer.
Fruiting heads, about 1½ inch in diameter, hanging on the tree during winter after the fall of the seeds in autumn, calyx margins with irregular small tubercules; capsules with two stout style appendages, forming woody spines, one terminating each valve. Perfect seeds few, with short terminal wing; imperfect seeds numerous, minute, angled, without wings.
The branchlets* of many trees of this species are remarkable for their corky wings, which begin to develop in the second season and increase in width and thickness for many years. These wings occur on lateral branches, on the upper side only, in three or four parallel ranks; but on vertical branches they are borne irregularly on all sides. Trelease? observed in the case of Liquidambar trees
1 See Miss Gregory in Botanical Gazette, xiii. 282 (1888).
? Garden and Forest, 1890, p. 195.
