Dioscorea gracillima Miq.

Chinese collections of this species have entire leaves with little or no suggestion of an undulate margin, whereas Japanese collections have leaves with an undulate to obscurely bluntly lobed margin. The type is from Japan.

Rhizome horizontal, irregular. Stem twining to left, glabrous. Leaves alternate, sometimes 3- or 4-whorled at stem base, simple; petiole 7--12 cm; leaf blade drying green or brownish, cordate, 10--18 × 6.5--11 cm, pruinose, glabrous, basal veins 7 or 9, base broadly cordate or subtruncate, margin entire or slightly undulate, apex acuminate. Male spike irregularly branched, laxly few flowered; rachis slender. Male flowers: solitary, rarely in cymules of 2 or 3 at inflorescence base, sessile; bracts ovate, membranous; bracteoles shorter and narrower than bracts; perianth saucer-shaped, lobes oblong-orbicular, 1.5--2 mm; stamens 3, anther connective ca. 1/2 as wide as anther; staminodes 3, inserted at margin of receptacle, clavate. Female spike solitary, laxly few flowered, to 7 cm. Female flowers: staminodes 6. Capsule reflexed, brown, oblong-ovoid, 2--2.2 cm, apex truncate; wings 1--1.1 cm wide. Seeds inserted near middle of capsule, ca. 1 cm in diam. (ca. 0.5 cm excluding wing), winged all round. Fl. May--Aug, fr. Jun--Oct.

S Anhui, N Fujian, SW Hubei, E Hunan, Jiangxi, Zhejiang [Japan].

Open forests, mountain slopes; 200--2200 m.

Dioscorea gracillima là một loài thực vật có hoa trong họ Dioscoreaceae. Loài này được Miq. mô tả khoa học đầu tiên năm 1867.

纤细薯蓣（学名：Dioscorea gracillima）是薯蓣科薯蓣属的植物。分布于日本以及中国大陆的湖南、福建、浙江、江西、安徽、湖北等地，生长于海拔200米至2,200米的地区，多生长于山坡疏林下、阴湿的山谷和河谷地带，目前尚未由人工引种栽培。