2. MACLURA Nutt.
Toxylon (Ioxylon) Rafn.
A tree, with thick milky slightly acrid juice, thick deeply furrowed dark orange-colored bark, stout tough terete pale branchlets, with thick orange-colored pith, lengthening by an upper axillary bud, marked by pale orange-colored lenticels and armed with stout straight axillary spines, short stout spur-like lateral branchlets from buds at the base of the spines, and thick fleshy roots covered by bright orange-colored bark exfoliating freely in long thin persistent papery scales. Leaves involute in the bud, ovate to oblong-lanceolate, acuminate and apiculate at apex, rounded, cuneate or subcordate at base, entire, penniveined, the veins arcuate near the margins and connected by conspicuous reticulate veinlets; petioles elongated, slender, terete, pubescent; stipules lateral, nearly triangular, minute, hoary-tomentose, caducous. Flowers diœcious, light green, minute, appearing in early summer; calyx 4-lobed, the lobes imbricated in æstivation; the staminate long pedicellate, in short or ultimately elongated racemes borne on long slender drooping peduncles from the axils of crowded leaves on the spur-like branchlets of the previous year; calyx ovoid, gradually narrowed into the slender pubescent pedicel, coated on the outer surface with pale hairs, divided to the middle into equal acute boat-shaped lobes; stamens 4, inserted opposite the lobes of the calyx on the margins of the minute thin pulvinate disk; filaments flattened, light green, glabrous, infolded above the middle in the bud, with the anthers inverted and back to back, straightening abruptly in anthesis and becoming exserted; anthers oblong, attached on the back near the middle, introrse, 2-celled, the cells attached laterally to a minute oblong or semiorbicular connective, free and spreading above and below, opening by longitudinal lateral slits; pistillate sessile in dense globose many-flowered heads on short stout peduncles axillary on shoots of the year; calyx ovoid, divided to the base into oblong thick concave lobes, rounded, thickened, and covered with pale hairs at the apex, longer than the ovary and closely investing it, the 2 outer lobes much broader than the others, persistent and inclosing the fruit; ovary ovoid, compressed, sessile, green, and glabrous; style covered by elongated slender filiform white stigmatic hairs; ovule suspended from the apex of the cell, anatropous. Drupes oblong, compressed, rounded and often notched at apex, acute at base, with thin succulent flesh, and a thin crustaceous light brown nutlet, joined by the union of the thickened and much elongated perianths of the flowers into a globose compound fruit saturated with milky juice, mammillate on the surface by their thickened rounded summits, light yellow-green, usually of full size but seedless on isolated pistillate individuals. Seed oblong, compressed, rounded at base, oblique and marked at apex by the conspicuous oblong pale hilum, without albumen; seed-coat membranaceous, light chestnut-brown; embryo recurved; cotyledons oblong, nearly equal; radicle elongated, incumbent, ascending.
The genus is represented by a single species of eastern North America.
The generic name is in compliment to William Maclure, distinguished geologist.
1. [Maclura pomifera] Schn. Osage Orange. Bow Wood.
Toxylon (Ioxylon) pomiferum Rafn.
Leaves 3′—5′ long, 2′—3′ wide; turning bright clear yellow before falling in the autumn; petioles 1½′—2′ in length. Flowers: racemes of the staminate flowers 1′—1½′ long; heads of the pistillate flowers, ¾′—1′ in diameter. Fruit 4′—5′ in diameter, ripening in the autumn, and soon falling to the ground.
A tree, sometimes 50°—60° high, with a short trunk 2°—3° in diameter, and stout erect ultimately spreading branches forming a handsome open irregular round-topped head, and branchlets light green often tinged with red and coated with soft pale pubescence when they first appear, soon becoming glabrous, light brown slightly tinged with orange color during their first winter, and ultimately paler. Winter-buds depressed-globose, partly immersed in the bark, covered by few closely imbricated ovate rounded light chestnut-brown ciliate conspicuous scales. Bark ⅔′—1′ thick, and deeply and irregularly divided into broad rounded ridges separating on the surface into thin appressed scales. Wood heavy, exceedingly hard, very strong, flexible, coarse-grained, very durable, bright orange color turning brown on exposure, with thin light yellow sapwood of 5—10 layers of annual growth; largely used for fence-posts, railway-ties, wheel-stock, and formerly by the Osage and other Indians west of the Mississippi River for bows and war-clubs. The bark of the roots contains moric and morintannic acid, and is used as a yellow dye. The bark of the trunk is sometimes used in tanning leather.
Distribution. Rich bottom-lands; southern Arkansas to southern Oklahoma and southward in Texas to about latitude 35° 36′; most abundant and of its largest size in the valley of the Red River in Oklahoma.
Largely planted in the prairie regions of the Mississippi basin as a hedge plant, and occasionally in the eastern states; hardy in New England; occasionally naturalized beyond the limits of its natural range.