This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
This genus differs mainly from the last in having only one of the outer petals spurred or inflated, the other being flat, and in the inflated 2-valved capsule; the flowers are also smaller. The Greek name for Fumitory. Species numerous in the Mediterranean region, a few extending to America, South Africa, and north-western Asia.
1. G. lutea. - A common European plant, found naturalised in some parts of England. A perennial fibrous-rooted herb, about a foot high. Leaves on long petioles, ternately divided. Flowers yellow, in leaf-opposed racemes, from May to August.
2. G. nobilis. - This is a fine large yellow-flowered species, a native of Siberia, producing its flowers in early Spring. It belongs to the tuberous-rooted section, and has unbranched stems about a foot high, and dense racemes of bright yellow flowers.
G. Marshalliana is a dwarf tuberous-rooted species from Asia Minor, having pale yellow racemose flowers and a pair of biternate leaves on each stem; G. solida is a tufted species about 6 inches high, with biternate glaucous leaves and unilateral racemes of rosy flowers from the axils of laciniate bracts; and C. tuberosa, syn. G. cava, is similar to the last, with white flowers and entire bracts. These two are both European species.