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 family contains three or four distinct and pretty species, some or all of which should be cultivated in every collection of hardy border plants. They are hardy elegant plants adapted to any purpose to which herbaceous plants may be turned.
This is one of the most elegant and interesting, though not the showiest, of the group. It grows in graceful rounded masses, a foot or more high, with elegant compound leaves on slender hard smooth stalks, with lively green heart-shaped leaflets, bronzed and rigidly ciliated on the margin. The flowers in long loose racemes spring from the leafstalks an inch or two below the primary divisions of the leaves, are small, reddish brown, with curious spurred yellow and rather conspicuous corollas.
This is the finest of Epimediums, and a very handsome and interesting, plant. It is less vigorous in growth than the last species, growing from 6 inches to 1 foot high, with leaves of the same structure and general form, but smaller, and usually bronzed and shining in the early stages of growth; the margins ciliated and the stalks slightly hairy. The flowers are white, tinted with purple, and the petals, about an inch long and four in number, are pure white, transparent, and are the most conspicuous feature in the flower. The flower-stalks carry the flowers slightly above the bronzy foliage, and the effect produced is charming. Flowers April and May. Native of Japan, but quite hardy.
This species grows about the same height as the large-flowered Epimedium, with smaller leaflets supported on more slender stalks. The flowers, borne in rather dense racemes, are yellowish, and appear in April and May. The variety named elegans is the best, and is a very desirable plant for partially-shaded borders. Native of Persia.
The leaflets in this species are narrower in proportion to the breadth than in the last two species. The flowers are white, tinted with pale purple, and appear in April and May. By some this is regarded, and not without reason, as a variety of the large-flowered Epimedium; the stature and habit in both forms are nearly the same, and in other respects they are not markedly distinct for the purposes of decoration. Native of Japan.