Corydalis is a genus of about 300 species of annual and perennial herbaceous flowering plants in the family Fumariaceae, native to the temperate Northern Hemisphere and also southern Africa. Common names include corydalis and fumewort.
It is closely related to Fumaria, and some botanists include it in that genus.
Characteristics - C. lutea
Yellow Corydalis grows 30-38 cm (12 to 15 inches) tall and its gray-green foliage is attractive from spring until fall. The 2 cm (3/4 inch) flowers are borne above the leaves from spring until mid-summer and sometimes later. The species often grows wild in cracks in old walls where drainage is excellent.
How to Grow C. lutea
Yellow Corydalis grows in USDA Hardiness Zones 5 to 10 (average annual minimum temperature –29°C or above); it does best in light shade, but will tolerate both full sun and deep shade. Excellent drainage is vital and the soil should be liberally supplemented with peat moss or leaf mold. Set plants 8 to 10 inches (~ 20-25 cm) apart. New plants can be started by dividing and resetting clumps in early spring after two or three years of flowering or from stem cuttings taken in summer for flowers the following year. To prevent overcrowding, divide clumps after two of three years of flowering.
Corydalis species are used as food plants by the larvae of some Lepidoptera species including Silver-ground Carpet.
Corydalis contains the alkaloid bulbocapnine, which is occasionally used in medicine.