This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
This is one of the most free and continuous-flowering genera in the order. It is not of the most showy description, but is always interesting and pretty. It succeeds best in partial shade, and is useful for introducing into open woods and naturalising on shady banks where the vegetation is not of too encroaching a nature. Propagate by seeds in the open ground, in March, the double form by division in spring, or both by the latter means.
It is not so much for the species in its normal form that this plant is selected, as for two varieties of it of more value than itself, floriculturally speaking. The one is Chelidonium Majus flore pleno, a double-flowered variety, differing only from the simple form of the species in that particular. It grows about 18 inches high, in soft rounded outline, producing pale-green pinnately divided leaves.
The flowers are numerous, consisting in the simple form of only two sepals and two petals, but in the double variety the petals are indefinitely increased. The other variety is Chelidonium Majus variegata, and is distinguished from the species by having the foliage marked with creamy yellow. There is also a white-flowered variety, which may not be considered much of an acquisition where the others are cultivated, and there is a number of botanically interesting varieties, the species being of a variable nature; flowers from April and May till October ; native of Britain.