''Corydalis solida'', syn. ''C. halleri'', ''C. transsylvanica'' , is a species of flowering plant in the family Papaveracae, native to moist, shady habitats in northern Europe and Asia. Growing to 25 cm , it is a spring ephemeral, with foliage that appears in spring and dies down to its tuberous rootstock in summer. It is cultivated for its deeply divided, ferny leaves and narrow, long-spurred flowers which appear in spring. The flowers show color variation, and may be mauve, purple, red, or white.