《中国植物志》|| 薯蓣科 DIOSCOREACEAE ||根状茎组 Sect. Stenophora Uline ||穿龙薯蓣 Dioscorea nipponica Makino

1. 穿龙薯蓣（中国药用植物志）穿山龙（东北、山西），山常山（山东）图版14: 1-4
Dioscorea nipponica Makino Ill. Fl. Jap. 1: t. 45. 1891; Prain et Burkill in Journ. Asiat. Soc. Bengal 73: suppl. 8. 1904 et n. s. 10: 13. 1914; R. Knuth in Engl. Pflanzenr. 87 (4-43): 314. 1924; Kudo in Jap. Journ. Bot. 2: 250. 1925; Prain et Burkill in Ann. Bot. Gard. Calcutta 14 (1): 61, Pl. 24. 1936. ——D. acerifolia Uline ex Diels in Engl. Bot. Jahrb. 29, 261. 1900. ——D. giraldii R. Knuth, l. c. 315.
缠绕草质藤本。根状茎横生，圆柱形，多分枝，栓皮层显著剥离。茎左旋，近无毛，长达5米。单叶互生，叶柄长10-20厘米；叶片掌状心形，变化较大，茎基部叶长10-15厘米，宽9-13厘米，边缘作不等大的三角状浅裂、中裂或深裂，顶端叶片小，近于全缘，叶表面黄绿色，有光泽，无毛或有稀疏的白色细柔毛，尤以脉上较密。花雌雄异株。雄花序为腋生的穗状花序，花序基部常由2-4朵集成小伞状，至花序顶端常为单花；苞片披针形，顶端渐尖，短于花被；花被碟形，6裂，裂片顶端钝圆；雄蕊6枚，着生于花被裂片的中央，药内向。雌花序穗状，单生；雌花具有退化雄蕊，有时雄蕊退化仅留有花丝；雌蕊柱头3裂，裂片再2裂。蒴果成熟后枯黄色，三棱形，顶端凹入，基部近圆形，每棱翅状，大小不一，一般长约2厘米，宽约1.5厘米；种子每室2枚，有时仅1枚发育，着生于中轴基部，四周有不等的薄膜状翅，上方呈长方形，长约比宽大2倍。花期6-8月，果期8-10月。
分布于东北、华北、山东、河南、安徽、浙江北部、江西（庐山）、陕西（秦岭以北）、甘肃、宁夏、青海南部、四川西北部。常生于山腰的河谷两侧半阴半阳的山坡灌木丛中和稀疏杂木林内及林缘，而在山脊路旁及乱石覆盖的灌木丛中较少，喜肥沃、疏松、湿润、腐殖质较深厚的黄砾壤土和黑砾壤土，常分布在海拔100-1700米，集中在300-900米间。也产于日本本州以北及朝鲜和苏联远东地区。模式标本采自日本。
根状茎含薯蓣皂苷元是合成甾体激素药物的重要原料；民间用来治腰腿疼痛、筋骨麻木、跌打损伤、咳嗽喘息。

《Flora of China》|| Dioscoreaceae || Dioscorea ||穿龙薯蓣 Dioscorea nipponica

1. Dioscorea nipponica Makino, Ill. Fl. Jap. 1(7): 2. 1891.

穿龙薯蓣 chuan long shu yu

Rhizome horizontal, many branched, cylindric, more than 1.5 cm thick; cork layer persistent or readily detached. Stem twining to left, drying green or reddish brown, to 5 m, glabrescent. Leaves alternate, simple; petiole 10--20 cm; leaf blade shiny, drying yellowish green, broadly cordate to palmately unequally 3--7-lobed, very variable in shape, 7--15 × 4--13 cm, glabrous or sparsely minutely setose especially along veins, basal veins 7 or 9, outermost ones often forked, base cordate, margin undulate to prominently bluntly toothed or lobed, apex acuminate. Male spike solitary, to 17 cm, rarely with occasional cymules expanded to form lateral branches. Male flowers: usually in cymules or umbellules of 2--4(--7), solitary distally on inflorescence, sessile or shortly pedicellate; bracts lanceolate, slightly shorter than perianth; bracteoles ± obsolete; perianth saucer-shaped, lobes obtuse at apex; stamens 6, inserted at middle of perianth lobes, anthers introrse. Female flowers: staminodes filiform; stigma 3-lobed. Capsule reflexed at maturity, light brown, purplish speckled, ellipsoid-oblanceolate, 1.5--2 cm, base rounded, apex shallowly emarginate; wings 0.7--0.8 cm wide. Seeds inserted near base of capsule, sometimes only 1 fertile, winged all round but wing much wider toward capsule apex. Fl. Jun--Aug, fr. Aug--Oct.

Mixed forests, scrub forests, warm-temperature transitional areas; 100--1800 m. Anhui, Gansu, Guizhou, Hebei, Heilongjiang, Henan, Hubei, N Jiangxi, Jilin, Liaoning, Nei Mongol, Ningxia, S Qinghai, Shaanxi, Shandong, Shanxi, NW Sichuan, N Zhejiang [Japan, Korea, Russia].

The rhizome is an important source of steroids for the drug industry.