Vasilis Teodoridis:
Dioscoreaceae | Dioscorea
42. Dioscorea japonica Thunberg in Murray; Syst. Veg.; ed. 14. 889. 1784.
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Tubers vertical; long cylindric; to 3 cm in diam.; cork yellowish brown; transverse section white or yellowish white. Stem twining to right; green; sometimes light purplish red. Bulblets often present. Leaves alternate basally on stem; opposite distally on stem; simple; petiole 1.5--4(--6) cm; leaf blade drying yellowish green to light brownish; broadly ovate basally on stem; usually triangular-lanceolate to linear distally on stem; 3--12(--19) x 1--6(--18) cm; membranous or papery; glabrous; basal veins 5--9; base sagittate or hastate to cordate or ± truncate; margin entire; apex acute to long acuminate. Male spikes 3--5 together; rarely solitary; ± erect or ascending; 2--8 cm; rachis straight; occasionally slightly zigzagged at apex. Male flowers: perianth greenish white or light yellow; lobes purple spotted; ovate or ovate-elliptic; to 2 x 1.5 mm; inner ones smaller than outer; stamens 6. Female spikes solitary or 2 or 3 together; 6--20 cm. Female flowers: staminodes 6. Capsule not reflexed; pale brown with darker; linear freckles; oblate; 1.5--2(--2.5) cm; base truncate; apex emarginate; wings 0.7--1.5(--2) cm wide; margin dark. Seeds inserted near middle of capsule; D-shaped; ca. 1.9 cm (ca. 0.7 cm excluding wing); winged all round. Fl. May--Oct; fr. Jul--Nov.
Mixed forests and margins; scrub forests; herb communities; mountain slopes; valleys; along rivers and streams; roadsides; 100--1200 m. Anhui; Fujian; Guangdong; Guangxi; E and S Guizhou; Hubei; Hunan; Jiangsu; Jiangxi; Sichuan; Taiwan; Zhejiang [Japan; Korea].
Vasilis Teodoridis:
Dioscoreaceae | Dioscorea
42. Dioscorea japonica Thunberg in Murray; Syst. Veg.; ed. 14. 889. 1784.
???? ri ben shu yu
Tubers vertical; long cylindric; to 3 cm in diam.; cork yellowish brown; transverse section white or yellowish white. Stem twining to right; green; sometimes light purplish red. Bulblets often present. Leaves alternate basally on stem; opposite distally on stem; simple; petiole 1.5--4(--6) cm; leaf blade drying yellowish green to light brownish; broadly ovate basally on stem; usually triangular-lanceolate to linear distally on stem; 3--12(--19) x 1--6(--18) cm; membranous or papery; glabrous; basal veins 5--9; base sagittate or hastate to cordate or ± truncate; margin entire; apex acute to long acuminate. Male spikes 3--5 together; rarely solitary; ± erect or ascending; 2--8 cm; rachis straight; occasionally slightly zigzagged at apex. Male flowers: perianth greenish white or light yellow; lobes purple spotted; ovate or ovate-elliptic; to 2 x 1.5 mm; inner ones smaller than outer; stamens 6. Female spikes solitary or 2 or 3 together; 6--20 cm. Female flowers: staminodes 6. Capsule not reflexed; pale brown with darker; linear freckles; oblate; 1.5--2(--2.5) cm; base truncate; apex emarginate; wings 0.7--1.5(--2) cm wide; margin dark. Seeds inserted near middle of capsule; D-shaped; ca. 1.9 cm (ca. 0.7 cm excluding wing); winged all round. Fl. May--Oct; fr. Jul--Nov.
Mixed forests and margins; scrub forests; herb communities; mountain slopes; valleys; along rivers and streams; roadsides; 100--1200 m. Anhui; Fujian; Guangdong; Guangxi; E and S Guizhou; Hubei; Hunan; Jiangsu; Jiangxi; Sichuan; Taiwan; Zhejiang [Japan; Korea].