油楠 you nan

Trees, 8-20 m tall. Trunk 30-60 cm d.b.h. Leaves 10-20 cm; petiolules ca. 5 mm; leaflets 2-4 pairs, opposite, elliptic-oblong, rarely ovate, 5-10 × 2.5-5 cm, lateral veins slender, together with reticulate veinlets obscure, base rounded, slightly oblique, apex obtusely acute or shortly acuminate. Panicles in axils of apical leaves, 15-20 cm, densely yellowish pubescent; bracts ovate, leaflike, 5-7 mm. Pedicels 2-4 mm, with 1 or 2 bracteoles from middle upward; bracteoles linear-lanceolate, 5-6 mm; bracts, pedicels, and bracteoles densely yellowish pubes­cent. Calyx lobes yellowish pubescent on both surfaces, dimor­phic, uppermost one broadly ovate, ca. 5.5 × 5 mm, back arcu­ate, with 21-23 soft bristles, other 3 elliptic-lanceolate, with 6-10 soft bristles. Petal 1, enclosed in uppermost calyx lobe, ob­long-orbicular, ca. 5 × 2-6 mm, outside densely pubescent, in­side glabrous, base subtruncate, obscurely clawed, margin cili­ate, apex rounded. Fertile stamens 9, staminal tube ca. 2 mm, both sides adpressed brown strigose, especially inside; anthers subequal in size, 2-3 mm, apex emarginate, sometimes cuspi­date. Ovary ca. 3 mm, densely strigose, 4- or 5-ovuled; stalk ca. 0.8 mm; style convolute, glabrous. Legume orbicular or elliptic, 5-8 × ca. 5 cm, with dispersed, hard, straight prickles; valves often shedding glue when cut. Seed solitary, blackish, spher­oidal, ca. 1.8 cm in diam. Fl. Apr-May, fr. Jun-Aug.

● Mixed forests, mountain slopes, riverbanks; near sea level to 800 m. Fujian, Guangdong, Hainan, Yunnan.

The wood has good qualities and is used for building houses and making furniture.