日本七叶树 ri ben qi ye shu

Aesculus turbinata f. pubescens (Rehder) Ohwi ex Yas. Endo; A. turbinata var. pubescens Rehder.

Trees to 30 m tall, to 2 m d.b.h. Branchlets pubescent when young. Petiole 7.5-25 cm, glabrous or pubescent; leaf blade 5-7-foliolate; leaflets sessile, abaxially slightly glaucous, oblanceolate, 15-35 × 5-15 cm, abaxially glabrous except villous in axils of lateral veins, or pubescent and more densely so on veins, base cuneate, margin shallowly crenate with crenations crenulate, apex abruptly acuminate; lateral veins in 18-26 pairs. Inflorescence glabrous or pubescent; peduncle 2-4 cm; thyrse conic or cylindric-conic, 12-25(-45) cm, 6-11 cm wide at base; branches up to 5 cm, 5-10-flowered; pedicels 3-4 mm. Calyx 3-5 mm, abaxially pubescent. Petals 4(or 5), white or pale yellow, with red spots and a yellow (later red) claw, unequal, 2 oblong and 2 oblong-obovate, 7-11 × 3-7 mm, abaxially pubescent. Stamens 6-10, 10-18 mm; filament sparsely villous; anther 1-1.5 mm. Style tomentose, sparsely so
near apex. Capsule dark brown, broadly obovoid or pyriform, 2.5-5 cm in diam., verrucose; verrucae low, suborbicular, unequal, 0.5-2 mm in diam.; pericarp 3-6 mm thick after drying. Seed usually 1, reddish brown, ± globose, 2-3 cm; hilum pale brown, occupying ca. 1/2 of seed. Fl. May-Jul, fr. Sep. 2n = 40.

Introduced to China, cultivated in parks; 100-200 m. Shandong (Qingdao), Shanghai [native to Japan].

Aesculus turbinata is cultivated as an ornamental and for its timber. It has been confused in China with A. chinensis, but it differs in several characters, including its sessile (vs. petiolulate) leaflets, crenulate (vs. serrulate) leaflet margin, conic or cylindric-conic (vs. cylindric) thyrse, and verrucose (vs. dotted but smooth) capsule.