Description from Flora of China
Corydalis cavaleriei H. Léveillé & Vaniot; C. ecalcarata (Z. Y. Su) Y. H. Zhang; C. formosana Hayata; C. lofouensis H. Léveillé; C. nokoensis Hayata; C. omphalocarpa Hayata; C. orthocarpa Hayata; C. pseudotomentella Fedde; C. racemosa (Thunberg) Persoon var. ecalcarata Z. Y. Su; C. taitoensis Hayata; C. tashiroi Makino.
Herbs, annual, glaucous, 15-50 cm, with simple taproot. Stems ridged, slender, branched and leafy throughout. Leaves: petiole 4-13 cm; blade pale abaxially, green adaxially, ovate to ovate-oblong, or lower leaves triangular, 7-15 × 6-10 cm, bipinnate; pinnae distant, (2 or)3 or 4 pairs, petiolulate; pinnules 1 or 2 pairs, almost sessile, deeply divided into 3-5 oblong to ovate mucronulate lobes. Raceme lax, 3-15-flowered, first produced raceme usually longer and many flowered; bracts ovate to lanceolate, 4-7 mm, acute to shortly acuminate. Pedicel 3-5 mm. Sepals ovate, 1(-2?) mm, dentate. Corolla yellow to yellowish white. Outer petals narrow, retuse to truncate, dentate with short dentate crest not reaching apex; upper petal 15-17 mm (smaller in cleistogamous flowers); spur saccate, ca. 3 mm; nectary 1/3-1/2 of spur; inner petals 10-12 mm, dorsal crests rounded, overtopping apex. Stigma horizontally extended 2-armed, each 1/2 with 1 distinct apical forward-projecting papillae and diffuse terminal papillae (possibly 2 confluent). Capsule linear, straight, 30-44 × 2-3 mm; style 3-4 mm. Seeds in 1 row, 1.5-1.8 mm, lenticular with linear impressions in concentric rows; caruncle large, membranous, folded back over seed. Fl. and fr. May-Aug.
Some plants from Taiwan differ in the broader limbs of outer petals.
Valleys, wet areas, thickets on foothills; 200-700 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangsu, Jiangxi, Shandong, Taiwan, Yunnan (Funing, Hekou), Zhejiang [Japan (Ryukyu Islands), Laos, Vietnam].