- Scientific Name: Corydalis yanhusuo (Y.H.Chou & Chun C.Hsu) W.T.Wang ex Z.Y.Su & C.Y.Wu
- Ref: Acta Bot. Yunnan. 7:269. 1985
- Synonym: Corydalis turtschaninovii f. yanhusuo Y.H.Chou & Chun C.Hsu
- English Common Name: Asian corydalis
- Chinese Common Name: 延胡索 yánhúsuǒ, 元胡 yuánhú
- Japanese Common Name: エンゴサク [延胡索] engosaku
- Family: Papaveraceae
- Genus: Corydalis
- Distribution: Grasslands on highlands. Anhui, Henan (Tanghe, Xinyang), Hubei, Hunan, Jiangsu, Zhejiang; cultivated in Beijing, Gansu, Shaanxi, Sichuan, and Yunnan.
Herbs, perennial. Tuber yellow, rounded, (0.5-)1-2.5 cm in diam. Stems erect, 10-30 cm, with 1 or sometimes 2 scale leaves, with 2 or often 3(or 4?) cauline leaves, scales and lower cauline leaves often with axillary tuber. Leaves biternate or nearly triternate; leaflets 2-2.5 cm × 5-8 mm, entire to deeply trifid with lanceolate entire acute segments; lowermost cauline leaf often long petiolate and vaginate at base. Raceme lax, 5-15-flowered; bracts lanceolate or narrowly ovate, 5-12 × 2-5 mm, margin entire, apex acute, sometimes lower bracts slightly divided. Pedicel ca. 10 mm at flowering, in fruit to 20 mm. Flowers amaranth. Sepals caducous, small. Outer petals with broad dentate limbs, emarginate with a mucro in notch; spur of upper petal upcurved, cylindric, 11-13 mm; nectary extended through ca. 1/2 of spur, apex obtuse; lower petal with short claw; inner petals 8-9 mm, claw longer than petal lobes. Stigma nearly orbicular, papillae longer than in preceding species. Capsule linear, 20-28 mm. Seeds in 1 row. Fl. and fr. Apr-Jun. (Flora of China)
