The name 'clematis' is derived from the Greek word klema, meaning vine branch or vine-like. It is possible that even before the use of the word 'Klema-tis' the whole genus was known as atragene, meaning 'firecracker' in Greek. Apparently, when large dry stems of C. vitalba are placed in a fire, the heat causes them to split, making a noise like firecrackers. Although the Atragene group now embraces C. alpina, C. macropetala and similar North American species, atragene was at one time used as a name for C. vitalba.
C. flammula, in which the flowers are without involucre or petals and the achenes or seed-like fruits are lengthened out into a bearded, feathery tail- represented by C. flammula.
C. viticella, in which the flowers are as in C. flammula, but the achenes have only a short, and not a plumose, tail - represented by C. viticella.
Cheiropsis, in which there are two bracted calyx-like involucres at the top of the pedicels, no petals and a bearded plumose tail to the achenes - represented by C. calycina [now C. cirrhosa].
Atragene, in which there is no involucre, the outer stamens passing gradually into the petaloid staminodes and the achenes having a bearded plumose tail - represented by C. alpina.
Moore and Jackman also recorded that in 1877 scientific records showed that some 230 clematis species had been identified. Of these, some 17 were European, chiefly occurring in the southern and eastern regions; 43 were of Indian origin; 9 were Javanese; approximately 30, comprising some of the finest species, came from China and Japan (we now know that 108 species are native to China); 11 were from the Siberian regions; 2 were from the Fiji Islands; 24 were from South America; 9 species were from Central America and the West Indies; 35 species were North American; 14 species came from tropical Africa; 4 were from South Africa; 6 species were from the Mascarene Islands and Madagascar; 15 species were recorded as coming from New Holland (Australia) and 5 from New Zealand. Many of these species have lost favor and are obviously not now in cultivation.
The early records show that some of the European species started to find their way to British gardens as early as 1569. When C. viticella was introduced, the only clematis found in British gardens up until then was the native C. vitalba, a rampant scrambler and climber that reaches 9-12m (30-40ft). C. vitalba's greatest contribution to the British countryside is, of course, its marvelous fluffy seed heads, which are outstanding on a frosty winter's day. C. viticella was to become a most important species in the early breeding work and can still help improve today's clematis, especially when one remembers that neither it nor its small-flowered cultivars succumb to clematis wilt. Its other great asset is its very free-flowering habit.
By the end of the 16th century, other European clematis had arrived on English shores: C. cirrhosa, C .flammula, C. integrifolia and C. recta. Because it is only semi-hardy C. cirrhosa has not established in English gardens other than in milder climates, which is a great shame as it has attractive winter flowers and evergreen foliage. A larger flowered cultivar, C. cirrhosa 'Freckles' appears more winter hardy and its flowers are borne in late autumn and early winter in England.
C. flammula is a very variable species and again it has not established widely in British gardens, perhaps because of its preference for dry, free draining soils. It is to be hoped that its variable habit will allow a form to be found that will establish well in the British Isles and countries of similar climatic conditions.
C. integrifolia is a most useful mixed border flower, together with some of the more recent introductions of good blue, pink and white forms, as well as the marvelous cultivar C. integrifolia 'Pangbourne Pink'.
C. recta is another very variable species, varying in flower size, form and height from plants that grow only to 90 cm (3 ft) to those reaching 1.8-2.1 m (6-7 ft). Good selected forms of C. recta should be found to enhance gardens both in Europe and in North America.
There were no introductions to the British Isles in the 17th century, but in the first quarter of the 18th century two useful American species, C. crispa and C. viorna, were introduced. Both should have been used more extensively in breeding work than they have been. C. crispa has scent to offer and the most delightful nodding flowers, and one of its progeny, C. viticella 'Betty Corning', has retained the scent. C. viorna, which is extremely free-flowering and has delightful seed heads, is a must for future breeding work.
During the 19th century various species were introduced into the British Isles from many areas around the world. C. florida 'Sieboldii' was introduced in the 1830s, but as it is sterile it was not possible to use it in breeding. However, the most important introductions during the 19th century which gave the breeders the greatest opportunity of all time to create new cultivars were C. patens and its cultivars in the 1830s, the amazing C. lanuginosa in 1851 and C. 'Fortunei' and C. 'Standishii' in 1863. After the arrival of these species and cultivars from Japan, the breeders of the British Isles, France, Belgium and Germany embarked upon a race to produce the best, most colorful cultivars.
One of the earliest clematis cultivars ever raised - possibly the first - was C. 'Eriostemon', though according to the Swedish nurseryman Magnus Johnson its origin is not known exactly. This clematis was probably raised in Belgium or the Netherlands before 1830. The clematis was described and pictured by Decaisne in Revue Horticole in about 1852, C. 'Eriostemon' being the result of a cross between C. viticella and C. integrifolia.
The next cultivar raised was C. 'Hendersonii' in 1835, produced also from crossing C. viticella with C. integrifolia. It was raised by Mr. Henderson in the Pine Apple Place Nursery, London. It was flowered for the first time by Mr. Chandler of Vauxhall, London, and has sometimes been called C. chandlerii. In the nursery trade, C. 'Eriostemon' and C. 'Hendersonii' are frequently sold incorrectly under the same name of C. x eriostemon 'Hendersonii', although they are two distinct flowers.
Although these two plants are very similar, coming from the same parentage, there are differences. Magnus Johnson describes the main difference as follows. Stem leaves near to the base of C. 'Eriostemon' are entire, broadly ovate or three to five-lobed; in C. 'Hendersonii', the stem leaves are entire, narrowly ovate or three-lobed. In C. 'Eriostemon', the upper stem leaves are pinnate with generally five acutely elliptic segments and in C. 'Hendersonii' the upper stem leaves are pinnate with five to seven lanceolate segments. The flowers are virtually the same in form, with tepal size slightly larger in C. 'Eriostemon'. The flower buds differ slightly also, with C. 'Eriostemon' having nodding, comparatively short conical buds, while C. 'Hendersonii' has long conical buds. The other flower components vary only slightly.
The most important step towards producing the very large-flowered clematis of today was made by Isaac Anderson-Henry of Edinburgh, Scotland, in 1855, when it is recorded that he crossed C. patens azurea grandiflora with C. lanuginosa. The resulting cultivar was C. 'Reginae', which was described as a handsome lavender-colored cultivar of intermediate character. It was shown in London in 1862 and gained a Certificate of Merit. Shortly afterwards, Anderson-Henry bred the world-famous C. 'Henryi' and C. 'Lawsoniana'. His detailed account of these later cultivars appeared in the Moore and Jackman book of 1877, where he described the crosses as coming from C. lanuginosa as the female or seed-bearer and C. 'Fortunei' as the male parent. C. lanuginosa and C. 'Fortunei' have long since been lost to cultivation but fortunately C. 'Lawsoniana' is still in commerce, although not grown widely, and C. 'Henryi' is sold in large quantities. Anderson-Henry recounts with excitement that 'Lawsoniana' had flowers which could reach up to 24 cm (9 1/2 in) across and describes his disbelief in the blue of this cultivar being considerably darker than either parent. C. lanuginosa is described as pale lilac and C. 'Fortunei' as having pure white semi double flowers. He points out that C. 'Fortunei' is probably a seedling from C. 'John Gould Veitch', a plant introduced from Japan in 1862 by Robert Fortune.
In cultivation cultivars with the C. lanuginosa type of habit produce flowers that have sported. One of these was C. 'Blue Gem', which should normally have pale lilac blue flowers with red anthers. If C. lanuginosa was found in a churchyard, by the time it was collected by Robert Fortune it may have already been a cultivated variety which had been planted in the churchyard. Further research needs to be done in this area.
Next in order of the new cultivars of the 19th century came the Woking hybrids, raised by Messrs George Jackman and Sons. These were the result of using C. lanuginosa with C. 'Hendersonii' and C. viticella atrorubens during the summer of 1858. The first plants reported to have bloomed were those named C. 'Jackmanii' and C. rubroviolacea in 1862. These were shown in 1863 in Kensington, presumably to the Royal Horticultural Society, receiving Certificates of Merit in the first class. C. 'Jackmanii' was to become one of the most outstanding clematis ever raised. Its free flowering habit and masses of flowers of a deep, intense violet-purple are easily recognizable on archways and porches throughout Europe and North America, where this clematis is particularly winter hardy.
In Europe, great work on producing new cultivars was also well underway. The British often criticized their European counterparts for producing clematis with gappy flowers, but the Europeans did rather well with the depth of flower color. The most successful European breeders were the Moser family, who gave us C. 'Nelly Moser' in1897 which, along with C. 'Jackmanii', is perhaps still one of the best-known clematis in the world. C. 'Marcel Moser' was introduced in 1896 but, overshadowed by the color and impact of 'Nelly Moser', it is somewhat forgotten today.
Other notable European contributors to clematis breeding during the latter half of the 19th century were M. Simon-Louis of Metz, M. Rim of Frankfurt, M. Carre of Troyes, M. Dauvesse of Orleans, M. Modeste-Guérin and M. Bonamy Frères.
Some 40 or so of those early cultivars are still listed by today's nurseries and sold in garden centers around the world. Included among them is C. 'Fair Rosamond', raised in 1881, which is still one of the few large flowered cultivars to have slight scent. During the 1880s, further cultivars were raised but some of the excitement had died down. One good clematis, C. 'Beauty of Worcester', raised by Messrs Smiths of Worcester around 1890, is still in cultivation. Its stunning double purple-blue flowers must have caused a sensation when this clematis was introduced.
By the turn of the century clematis wilt had started to appear and A. E. Jackman gave a lecture on the 'sickness', as it was called, to the Royal Horticultural Society. The interest in breeding subsided considerably as the sickness caused by clematis wilt (Phoma clematidina) became a serious threat to clematis nurserymen. The introduction of the various cultivars of C. patens from Japan and the inbreeding that subsequently took place of what was probably already inbred stock certainly would not have increased the plants' vigor. By this time, nurserymen were using C. vitalba or C. viticella as understock for grafting clematis, but using these, and particularly C. vitalba, did not help the sickness problem.
Plant collectors such as George Forrest and Ernest Wilson continued to bring back clematis species from China, increasing the range available until just before the First World War. Some of the most useful garden clematis brought back at that time were C. armandii and C. montana var. rubens in 1900, C. rehderiana in 1908, C. chrysocoma in 1910, C. fargesii (now known as C. potaninii var.fargesii) in 1911 and C. macropetala in 1912.
This was a period in which three men in particular made a notable contribution to the development of clematis as a garden flower: William Robinson, Ernest Markham and Percy Picton.
The plant named after Markham, C. 'Ernest Markham', is a bestseller worldwide. Grown and introduced by Jackmans of Woking from seedlings raised at Gravetye after Markham's death in 1937, it has recently been awarded the RHS Award of Garden Merit.