Gleditsia triacanthos L.
HABIT.—A tree usually 50-75 feet high, with a trunk diameter of 2-3 feet; dividing near the ground into several large, upright branches which divide again into long, slender, horizontal branchlets; both trunk and large branches armed with stout, rigid, simple or branched spines.
LEAVES.—Alternate, pinnately or bipinnately compound, 7-12 inches long. Leaflets 18 or more, 3/4-1-1/2 inches long, one-third as broad; lanceolate-oblong; remotely crenulate-serrate; thin; lustrous, dark green above, dull yellow-green beneath. Petioles and rachises pubescent.
FLOWERS.—May-June, when the leaves are nearly full grown; polygamo-dioecious; the staminate in short, many-flowered, pubescent racemes; the pistillate in slender, few-flowered racemes; on shoots of the preceding season; calyx campanulate, hairy 3-5-lobed; petals 3-5, greenish; stamens 3-10; ovary 1-celled, woolly.
FRUIT.—Autumn, falling in early winter; flat, pendent, twisted, brown legumes, 12-18 inches long, short-stalked in short racemes; seeds 12-14, oval, flattened.
WINTER-BUDS.—Terminal bud absent; lateral buds minute, 3 or more superposed, glabrous, brownish.
BARK.—Twigs lustrous, red-brown, becoming gray-brown; thick on the trunk, iron-gray to blackish and deeply fissured into long, narrow ridges roughened by small scales.
WOOD.—Hard, strong, coarse-grained, durable in contact with the ground, red-brown, with thin, pale sapwood.
DISTRIBUTION.—Indigenous to the extreme southern portion of the state, but is planted as far north as Bay City.
HABITAT.—Prefers deep, rich loam, but grows on a variety of soils.