Bark.—Bark of trunk dark, rough and seamy even in young trees, and armed with stout prickles which disappear as the tree matures; in old trees coarsely, deeply, and firmly ridged, not flaky; larger branches a dull brown, rough; branchlets grayish-brown, armed with prickles; season's shoots green, more or less rough-dotted, thin, and often striped.
Winter Buds and Leaves.—Winter buds minute, partially sunken within the leaf-scar. Leaves pinnately compound, alternate; petiole swollen at the base, covering bud of the next season; often with spines in the place of stipules; leaflets 7-21, opposite or scattered, ¾-1¼ inches long, about half as wide, light green; outline ovate or oval-oblong; apex round or obtuse, tipped with a minute point; base truncate, rounded, obtuse or acutish; distinctly short-stalked; stipellate at first.
Inflorescence.—Late May or early June. Showy and abundant, in loose, pendent, axillary racemes; calyx short, bell-shaped, 5-cleft, the two upper segments mostly coherent; corolla shaped like a pea blossom, the upper petal large, side petals obtuse and separate; style and stigma simple.
Fruit.—A smooth, dark brown, flat pod, about 3 inches long, containing several small brown flattish seeds, remaining on the tree throughout the winter.
Horticultural Value.—Hardy throughout New England in all dry, sunny situations, of rapid growth, spreading by underground stems, ordinarily short-lived and subject to serious injury by the attacks of borers. Occasionally procurable in large quantities at a low rate. In Europe there are many horticultural forms, a few of which are occasionally offered in American nurseries. The type is propagated from seed, the forms by grafting.
Plate LXVII.—Robinia Pseudacacia.
| 1. Winter buds. |
| 2. Flowering branch. |
| 3. Flower with corolla removed. |
| 4. Fruiting branch. |