Sophora japonica L.

  • Authority

    Isely, Duane. 1981. Leguminosae of the United States. III. Subfamily Papilionoideae: tribes Sophoreae, Podalyrieae, Loteae. Mem. New York Bot. Gard. 25 (3): 1-264.

  • Family

    Fabaceae

  • Scientific Name

    Sophora japonica L.

  • Description

    Species Description - Tree of glabrous aspect, 3-20 m. Leafstalk 1-2 dm, puberulent or glabrate, the petiole base covering bud; leaflets 9-15, petioluled, ovate to ovate-lanceolate, acute or apiculate, 3-4(-5) cm, 2-2.7 r, green and glabrous above, lighter and inevidently (-conspicuously) strigulose beneath. Flowers 12-17 mm, numerous in ample, puberulent, terminal, erect or pendent panicles above foliage (-and axillary racemes from upper leaves). Pedicels 4-5 mm, minutely bibracteolate. Calyx-hypanthium turbinate, 4.5-6 mm, often whitish-strigulose about orifice; lobes 5, 1-1.5 mm. Corolla cream, the petals subequal; standard suborbicular, lavender-striate with a basal yellowish oeil, recurved 90°-180°, remaining flat or slightly implicate; wings and keel petals 6-8 mm wide. Androecium adnate to hypanthium and shortly monadelphous. Pistil stipitate 3-4 mm; ovary cylindric, strigulose with light and dark hairs; ovules ca. 10; style short, incurved 90°-120°. Legume pendent, stipitate 5-25 mm (length of "stipe" depending on whether lower portion of pod is or is not sterile), irregularly moniliform, 2.5-6(-10) cm x 7-10 mm, with 1-5 segments that are separated or not by sterile intervals, persistent; valves fleshy and green when immature, black, glabrous and woody at maturity. Seeds 1-5, black. Styphnolobium.

  • Discussion

    S. japonica L. (1767); Styphnolobium japonicum (L.) Schott (1830). S. pubescens Tausch (1834). S. violacea Hort. 2n = 28 (Tschechow, 1931). The virtues of Sophora japonica, usually blooming in middle to late summer, are described by Everett (1971). Several horticultural varieties have been named (Rehder, 1940). Yakovlev’s (1967) segregate genus Styphnolobium, includes S. japonicum and S. affine. Sophora japónica differs from the remainder of the genus in chromosome number, but no count has been made for S. affine.

  • Distribution

    Occasional, Massachusetts to California. Native of China (not Japan), introduced in many temperate and warm countries as an ornamental. Cult ornamental and slightly escaped. (July-) Aug.-Sept. (-Nov.) Pagoda tree.

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