1. LIQUIDAMBAR L.
Trees, with balsamic juices, scaly bark, terete often winged branchlets, scaly buds, and fibrous roots. Leaves plicate in the bud, alternate, palmately lobed, glandular-serrate, long-petiolate; stipules lanceolate, acute, caducous. Flowers monœcious or rarely perfect in capitate heads surrounded by an involucre of 4 deciduous bracts, the staminate in terminal racemes, the pistillate in solitary long-stalked heads from the axils of upper leaves; staminate flowers without a calyx and corolla; stamens indefinite, interspersed with minute scales; filaments filiform, shorter than the oblong obcordate anthers opening longitudinally; pistillate flowers surrounded by long-awned scales, the whole confluent into a globular head; calyx obconic, its limb short or nearly obsolete; stamens usually 4, inserted on the summit of the calyx; anthers minute, usually rudimentary or abortive, rarely fertile; ovary partly inferior, of 2 united carpels terminating in elongated subulate recurved persistent styles stigmatic on the inner face; ovules numerous. Capsules armed with the hardened incurved elongated styles free above, septicidally dehiscent, consolidated by their base into a globose head; pericarp thick and woody; endocarp thin, corneous, lustrous on the inner surface. Seeds usually solitary or 2 by the abortion of many ovules, compressed, angulate; seed-coat opaque, crustaceous, produced into a short membranaceous obovate terminal wing rounded at the oblique apex.
Liquidambar with about four species is confined to the eastern United States, southern and central Mexico, Central America, southwestern Asia, middle and southeastern China, and Formosa. Liquid storax, an opaque grayish brown resin, is derived from Liquidambar orientalis Mill., a native of Asia Minor.
Liquidambar from liquidus and ambar in allusion to the fragrant juices.
1. [Liquidambar Styraciflua] L. Sweet Gum. Bilsted.
Leaves generally round in outline, truncate or slightly heart-shaped at base, deeply 5—7-lobed, with acutely pointed divisions finely serrate with rounded appressed teeth, when they unfold pilose on the lower surface, soon becoming glabrous with the exception of large tufts of pale rufous hairs in the axils of the principal veins, at maturity thin, bright green, smooth and lustrous, 6′—7′ across, with broad primary veins and finely reticulate veinlets; exhaling when bruised a pleasant resinous fragrance; in the autumn turning deep crimson; petioles slender, covered at first near the base with rufous caducous hairs, and 5′—6′ in length; stipules entire, glabrous, ⅓′—½′ long. Flowers: staminate in terminal racemes 2′—3′ long covered with rufous hairs, in heads stalked toward the base of the raceme and nearly sessile above, ¼′ in diameter, and surrounded by ovate acute deciduous hairy bracts much larger than the lanceolate acute bracts of the female inflorescence ½′ across and conspicuous from the broad stigmatic surfaces of the recurved and contorted styles. Fruit 1′—1½′ in diameter, persistent during the winter, the carpels opening in the autumn; seed ½′ long and rather longer than its wing, with a light brown coat conspicuously marked by oblong resin-ducts.
A tree, 80°—140° high, with a straight trunk 4°—5° in diameter, slender branches forming while the tree is young a pyramidal head, and in old age a comparatively small oblong crown, and slender branchlets containing a large pith, slightly many-angled, covered when they first appear with caducous rufous hairs, light orange color to reddish brown in their first winter, marked by occasional minute dark lenticels and by large arcuate leaf-scars showing the ends of 3 conspicuous fibro-vascular bundles, developing in their second season corky wings appearing on the upper side of lateral branches in 3 or 4 parallel ranks and irregularly on all sides of vertical branches, and increasing in width and thickness for many years, sometimes becoming 2′—3′ broad and 1′ thick. Winter-buds acute, ¼′ long, and covered by ovate acute minutely apiculate orange-brown scales rounded on the back, those of the inner rows accrescent, tipped with red, and about 1′ long at maturity. Wood heavy, hard, straight, close-grained, not strong, bright brown tinged with red, with thin almost white sapwood of 60—70 layers of annual growth; used for the outside and inside finish of houses, in cabinet-making, for street pavement, wooden dishes, and fruit boxes.
Distribution. Fairfield County, Connecticut, and in the neighborhood of the coast to southeastern Pennsylvania, southward to Cape Canaveral and the shores of Tampa Bay, Florida, and westward through southern Ohio, Indiana and Illinois to southeastern Missouri, and through Arkansas to eastern Oklahoma and the valley of the Trinity River, Texas; reappearing on the mountains of central and southern Mexico and on the highlands of Guatemala; in the maritime region of the south Atlantic and Gulf states and in the basin of the lower Mississippi River one of the common trees of the forest, covering rich river bottom-lands usually inundated every year; in the northern and middle states on the borders of swamps and low wet swales; at the north rarely more than 60°—70° tall, with a trunk usually not more than 2° in diameter.
Unsurpassed in the brilliancy of the autumnal colors of the leaves; and often planted as an ornamental tree in the eastern states.