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.
A noble genus of woody or herbaceous climbing plants, with usually opposite, ternate, or pinnate leaves, and twining petioles sometimes transformed into tendrils. Flowers in terminal or axillary panicles, rarely solitary. Sepals normally 4, but often more numerous, especially in the cultivated forms, coloured lilac, violet, or white. Petals none, or very much reduced, and passing gradually into stamens, which are very numerous. Carpels with persistent often beautifully bearded styles, lengthening considerably after the flowers have dropped. The species are numerous, and occur in the warm and temperate regions of the whole world. The name is of Greek origin.
1. C. Vitalba. Old Man's Beard, Lady's Bower. - The only native species; very abundant in the South of England in chalky districts. Leaves of 3 or 5 ovate variously toothed or lobed leaflets. Flowers fragrant, greenish white, very numerous, about one inch across, appearing in August, and followed by the feathery carpels.
2. G. Flammula. - A very beautiful species with pinnate leaves and small narrow lanceolate leaflets, and fragrant pure white flowers rather smaller than in the preceding. This is one of the commonest and oldest species in cultivation, and a very elegant plant for covering arbours and walls. A native of the South of Europe, flowering towards the end of Summer. There are several slight varieties of this species.
3. G. Montana. - Also an old inhabitant of our gardens, having trifoliolate leaves on a long peduncle; leaflets oval, more or less obtusely 3-lobed, with a few scattered hairs, and white solitary larger flowers. This species is a native of the South of Europe, and blooms in May, and valuable on that account.
4. C. Viorna (fig. 1). Leather Flower. - Flowers campanu-late, leathery, of a yellowish white, washed with bright purple on the outside. From North America, flowering in August.
5. C. Hendersoni. - A garden form, probably of hybrid origin, with large solitary reddish-violet flowers about 2 1/2 inches across; sepals broadly lanceolate and strongly nerved. A very hardy plant, now replaced by some of the larger-flowered garden hybrids of recent production. A late bloomer. This is sometimes referred to ft Viticella.
6. C. graveolens. - A small climbing undershrub, native of the higher mountains of Chinese Tartary. Leaves pinnately 3- to 5-foliolate; leaflets narrow, 3-lobed. Flowers solitary, yellow, of medium size. Perfectly hardy.
Fig. 1. Clematis Viorna. (1/6 nat. size.)
Fig. 2. Clematis Viticella. (1/4 nat. size.)
7. C. Viticella (fig. 2). - One of the best old sorts, and, crossed with G. lanuginosa, one of the parents of most of the gorgeous varieties raised by Mr. Jackman and others. Flowers purple, violet, or rose, single or semi-double, produced throughout the Summer. A native of Spain.
8. C. alpina, syn. Atragene alplna. - A dwarf climber, 3 or 4 feet high, with triternate hairy leaves and solitary rather large violet-blue flowers. In this the petals are imperfectly developed, passing gradually into stamens, and it is sometimes for that reason separated from Clematis. There is a white variety known as G. Sibirica. July.
9. C. Integrifdlia. - Stems dwarf, annual, with simple entire hairy leaves and solitary small blue flowers appearing in July, Native of the Pyrenees and mountains of Spain.
10. C. Florida. - A very beautiful Japanese plant, and an old inhabitant of our gardens, greatly modified by long cultivation. The leaves are composed of three or more oval leaflets, and the flowers are among the largest of the old sorts, solitary, single or double, pure white. The variety Sieboldii is a very ornamental plant, with white flowers having a purple-violet centre. The varieties of this plant are Summer bloomers and very handsome, but not so hardy as some others.
11. (C. azurea, including C. caerulea and C. patens (fig. 3). - Another Japanese species with ternate or biternate leaves and large solitary widely-expanded flowers 5 to 6 inches in diameter, composed of about 8 sepals in the single varieties. The normal tint is a pale blue or lilac, passing into white in some varieties. Amongst these varieties, monstrosa is remarkable for its semi-double flowers; Amalia has pale violet sepals, and Sophia is another single variety with immensely large and unusually broad sepals of a deep violet, with a longitudinal greenish band through the centre. This species is rather tender.
12. C. lanuginosa. - The leaves of this species are relatively large, and usually simple, broadly cordate, acute, glabrous above and hairy beneath. Flowers very large, solitary, formed of 6 or 8 spreading sepals of a palish blue or lilac. There is a variety of this known as pallida, with flowers not less than 9 or 10 inches across. A native of China, flowering in June.
13. C. Fortunei. - Like the last, of rather recent introduction, and also a very magnificent plant. Here the leaves are rather coriaceous, and usually 3-foliolate; leaflets cordate, rounded at the apex. Flowers fragrant, white, about 6 inches across, consisting of about a hundred oblong-lanceolate stalked sepals. This is quite hardy.
Fig. 3. Clematis azurea. (1/4 nat. size.)
Amongst the earlier hybrid varieties raised by Mr. G. Jackman, of Woking, who was, we believe, the first to institute experiments in crossing the species of this genus, we may mention rubro-violacea, with broadly oval or almost orbicular sepals of a reddish purple; and Jackmanii, of a rich violet purple. Owing to the remarkable success of this gentleman, several other horticulturists have followed his example, and the result is that many new varieties are offered every year.