Handsome clumps of dainty, divided leaves like those of bleed- ing heart (Dicentra, to which it is closely related) or maidenhair fern (Adiantum). Clusters of small, spurred flowers. Plant in rich, moist soil. Effective in rock crevices, in open woodland, near pool or streamside. Divide clumps or sow seed in spring or fall. Plants self-sow. Summer-flowering species may stop flowering during hottest months; keep soil moist to encourage some continued bloom.
C. 'Blackberry Wine'. Creeping habit, 1016 in. high and wide. Small, fragrant purple flowers. Will spill over walls. 'Berry Exciting' is similar except has soft yellow foliage and is sterile, so it won't reseed.
C. cheilanthifolius. Hardy Chinese native to 810 in. high and wide. Fernlike green foliage; clusters of yellow, -in.-long flowers in spring.
C. elata. Native to China. Upright grower to 15 in. high, 23 ft. wide. Heat-tolerant species that won't go dormant in summer; the best choice for the South. Cobalt-blue blossoms are carried above attractive, fleshy green leaves from spring through summer. Tantalizing fragrance has been described as a combination of gardenia and coconut.
C. flexuosa. BLUE CORYDALIS. From western China. Typically to 1 ft. high, 8 in. wide, but when conditions are favorable, it rapidly spreads more widely by bulblets on the roots. Finely divided blue-green leaves. Spikelike clusters of blue flowers appear in early spring, often continuing into summer. May go dormant in summer, especially in hot climates, but will reappear the following spring. Selections include gentian-blue 'Blue Panda', pure sky-blue 'China Blue', blue-and-lavender 'Nightshade', and lavender-to-light blue 'Pre David'. 'Purple Leaf', the earliest bloomer, has purplish blue flowers and purple-blotched green leaves.
C. heterocarpa. Native to Japan. Makes a 3- by 3-ft. blue-green mound. Rich yellow flowers cover the plant in late winter or early spring and continue to bloom intermittently throughout the growing season.
C. lutea. YELLOW CORYDALIS. Native to southern Europe. Grows to 15 in. tall, 1 ft. wide. Many-stemmed plant with masses of gray-green foliage. Bears golden yellow, 34-in.-long, short-spurred flowers throughout summer.
C. ophiocarpa. From the Himalayas. To 112 ft. tall and wide, 3 ft. tall in flower. Gray-green, feathery evergreen foliage. Blooms in spring, bearing cream-colored flowers with dark red tips.
C. solida. FUMEWORT. From northern Europe, Asia. Grows from tubers (sometimes available from bulb catalogs). To 10 in. high and 8 in. wide, with gray-green leaves and erect clusters of up to 20 purplish red, inch-long flowers in spring.