12. CLADRASTIS Raf.
A tree, with copious watery juice, smooth gray bark, slender slightly zigzag terete branchlets without a terminal bud, fibrous roots, and naked axillary buds 4 together, superposed, flattened by mutual pressure into an acuminate cone, and inclosed collectively in the hollow base of the petiole, the largest and upper one only developing, the lowest minute and rudimentary. Leaves unequally pinnate, petiolate, with a stout terete petiole abruptly enlarged at base, 7—11-foliolate, deciduous; leaflets usually alternate, broadly oval, the terminal one rhombic-ovate, contracted at apex into a short broad point, cuneate at base, entire, petiolulate, without stipels, covered at first like the young shoots with fine silvery pubescence, and on the midrib with lustrous brown tomentum, at maturity thin, glabrous, dark yellow-green on the upper surface, pale on the lower surface, the midrib and numerous primary veins conspicuous, light yellow below; stipules 0. Flowers on slender puberulous pedicels, bibracteolate near the middle, with scarious caducous bractlets, in long gracefully nodding stalked terminal panicles, the lower branches racemose, and often springing from the axils of 1-flowered pedicels, the main axis slightly zigzag, and, like the branches, covered at first with a glaucous bloom and slightly pilose; bracts lanceolate, scarious, pale, caducous; calyx cylindric-campanulate, enlarged on the upper side, and obliquely obconic at base, puberulous, 5-toothed, the teeth imbricated in the bud, nearly equal, short and obtuse, the 2 upper slightly united; disk cupuliform, adnate to the interior of the calyx-tube; corolla papilionaceous; petals white, unguiculate; standard nearly orbicular, entire or slightly emarginate, reflexed above the middle, barely longer than the straight oblong wing-petals, slightly biauriculate at the base of the blade, marked on the inner surface with a pale yellow blotch; keel-petals free, oblong, nearly straight, obtuse, slightly subcordate or biauriculate at base; stamens 10, free; filaments filiform, slightly incurved near the apex, glabrous; anthers versatile; ovary linear, stipitate, bright red, villose with long pale hairs, contracted into a long slender glabrous slightly incurved subulate style; stigma terminal, minute; ovules numerous, suspended from the inner angle of the ovary, superposed. Legume glabrous, short-stalked, linear-compressed, the upper margin slightly thickened, tipped with the remnants of the persistent style, 4—6-seeded, ultimately dehiscent, the valves thin and membranaceous. Seeds short-oblong, compressed, attached by a slender funicle; without albumen; seed-coat thin, membranaceous, dark brown; embryo filling the cavity of the seed; cotyledons fleshy, oblong, flat; radicle short, inflexed.
Four species are now known. One inhabits the southern United States, two occur in western China and one in Japan.
Cladrastis, from κλάδος and θραυστός, relates to the brittleness of the branches.
1. [Cladrastis lutea] K. Koch. Yellow Wood. Virgilia.
Leaves 8′-12′ in length, with leaflets 3′—4′ long and 1½′—2′ wide, the terminal leaflet rather shorter than the others and 3′—3½′ wide; turning bright clear yellow rather late in the autumn some time before falling. Flowers appearing about the middle of June, slightly fragrant, in panicles 12′—14′ long and 5′—6′ wide. Fruit fully grown by the middle of August, ripening in September and soon falling.
A tree, sometimes 50°-60° high, with a trunk 1½°—2° or exceptionally 4° in diameter, usually divided 6°—7° from the ground into 2 or 3 stems, slender wide-spreading more or less pendulous brittle branches forming a wide graceful head, and zigzag branchlets clothed with pubescence when they first appear, soon becoming glabrous, during their first season light brown tinged more or less with green, very smooth and lustrous, and covered by numerous darker colored lenticels, bright red-brown in their first winter and marked by large elevated leaf-scars surrounding the buds, and dark dull brown the following year. Bark of the trunk ⅛′—¼′ thick, with a silvery gray or light brown surface and rather darker colored than that of the branches. Wood heavy, very hard, strong and close-grained, with a smooth satiny surface, bright clear yellow changing to light brown on exposure, with thin nearly white sapwood; used for fuel, occasionally for gun-stocks, and yielding a clear yellow dye.
Distribution. Limestone cliffs and ridges generally in rich soil, and often overhanging the banks of mountain streams; Cherokee County, North Carolina, and the western slopes of the high mountains of eastern Tennessee; central Tennessee and Kentucky; near Florence, Lauderdale County, and cliffs of the Warrior River, Tuscaloosa County, Alabama; Forsythe, Taney County, and Eagle Rock, Barry County, Missouri; rare and local; most abundant in the neighborhood of Nashville, Tennessee, and in Missouri.
Often planted in the eastern United States as an ornamental tree, and hardy as far north as New England; and rarely in western and southern Europe; usually only flowering in alternate years.