Corydalis japonica Makino; C. makinoana Matsumura, nom. illeg. superfl.; C. streptocarpa Maximowicz.

Herbs, biennial (rarely annual), taprooted, glaucous. Stems few to several, ± erect, 40-100 cm, sometimes very thick, especially at base, conspicuously winged-ridged, leafy, branched. Basal leaves many, 10-50 cm; petiole ca. equal to blade, winged, especially broadly so toward base; blade oblong, bipinnate; primary pinnae 4-6 pairs, petiolulate; secondary pinnules 2(or 3) pairs, sessile, obovate to oblong, entire to 3-5-lobed; segments 3-10 × 1-5 mm, apex obtuse to rarely acute. Lower cauline leaves like basal leaves, upper ones smaller and much more shortly stalked. Racemes spikelike, long, 10-30 cm, 20-40(-70)-flowered (or fewer flowered in lateral racemes), with short peduncle; bracts linear-lanceolate, 2-5 mm. Pedicel 5-7 mm. Flowers pale yellow to whitish, usually dark tipped, 11-12 mm. Sepals ca. 1 × 1 mm, rarely to 3 mm, margin finely dentate, apex acute. Outer petals obtuse; spur ± ascending, broadly saccate, ca. 3 mm; nectary extended through ca. 1/2 of spur; inner petals 8-10 mm, tipped with dark purple, with crest clearly extending beyond apex, claw shorter than limb. Stigma bifid, lobes narrow, reflexed-geniculate with 2 papillae flanking apical division, one papilla terminating each lobe, and each lobe usually with a pair of submarginal geminate lateral papillae. Capsule reflexed, linear, strongly contorted, 20-30 × ca. 1.5 mm. Seeds in 1 row, black, shiny, ovoid, ca. 1 mm, pitted, keeled, with extended narrow straight caruncle. Fl. and fr. May-Aug.

River valleys, forest margins, woods, meadows; (200-)1100-2700(-4000) m. Anhui, Gansu, Guizhou, Hebei, Henan, Hubei, Hunan, Jiangxi, Ningxia, Qinghai, Shaanxi, Shanxi, Sichuan, Taiwan, Xizang, Yunnan [Bhutan, India (Sikkim), Japan].