Clematis

Clematis
Clematis 'Nelly Moser'
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
Order:	Ranunculales
Family:	Ranunculaceae
Subfamily:	Ranunculoideae
Tribe:	Anemoneae
Genus:	Clematis L.[1]
Species
See text.
Synonyms
Atragene L. Coriflora Weber Viorna Rchb.[1]

Clematis (KLEma-tis)^[2] is a genus of about 300 species^[3] within the buttercup family Ranunculaceae. Their garden hybrids have been popular among gardeners,^[4] beginning with Clematis × jackmanii, a garden standby since 1862; more hybrid cultivars are being produced constantly. They are mainly of Chinese and Japanese origin. Most species are known as clematis in English, while some are also known as traveller's joy, a name invented for the sole British native, C. vitalba, by the herbalist John Gerard; virgin's bower for C. viticella; old man's beard, applied to several with prominent seedheads; and leather flower or vase vine for the North American Clematis viorna.

Etymology

The genus name is from Ancient Greek clématis, ("a climbing plant"). There are over two hundred and fifty species and cultivars, often named for their originators or particular characteristics.

Botany

The genus is composed of mostly vigorous, woody, climbing vines / lianas. The woody stems are quite fragile until several years old.^[4] Leaves are opposite and divided into leaflets and leafstalks that twist and curl around supporting structures to anchor the plant as it climbs.^[4] Some species are shrubby, while others, like C. recta, are herbaceous perennial plants. The cool temperate species are deciduous, but many of the warmer climate species are evergreen. They grow best in cool, moist, well-drained soil in full sun.^[5]

Clematis species are mainly found throughout the temperate regions of the northern hemisphere, rarely in the tropics. Clematis leaves are food for the caterpillars of some Lepidoptera species, including the Willow Beauty (Peribatodes rhomboidaria).

The timing and location of flowers varies; spring-blooming clematis flower on side shoots of the previous year's stems, summer/fall blooming clematis bloom only on the ends of new stems, and twice-flowering clematis do both.^[4]

Species

Purple clematis

Clematis montana

Flowers of Clematis vitalba

Seed heads of Clematis vitalba growing in a hedge, showing why it is known colloquially as "old man's beard"

Clematis 'Multi Blue'

Achenes

Fruits of Clematis dioica in Guanacaste, Costa Rica

A partial list of species:

• Clematis addisonii Britt. – Addison's leather flower
• Clematis albicoma Wherry – whitehair leather flower
• Clematis alpina (L.) Mill. – alpine clematis
• Clematis aristata R.Br. ex Ker Gawl.^[6]
• Clematis armandii – Armand clematis
• Clematis baldwinii Torr. & A.Gray – pine hyacinth
• Clematis bigelovii Torr. – Bigelow clematis
• Clematis brachiata Thunb. – traveller's joy
• Clematis campaniflora Brot. – Portuguese clematis
• Clematis catesbyana – satin curls
• Clematis chinensis Osbeck – wei ling xian in Chinese (Chinese: 威靈仙; pinyin: Wei ling xian)
• Clematis chrysocoma Franch. – gold wool clematis
• Clematis cirrhosa L. – includes the 'Freckles,' 'Wisley Cream' and 'Jingle Bells' cultivars
  • Clematis cirrhosa v. balearica (Balearic Islands)
• Clematis coactilis (Fern.) Keener – Virginia whitehair leather flower
• Clematis columbiana (Nutt.) Torr. & A.Gray – British Columbia virgin's bower
• Clematis crispa L. – curly virgin's bower
• Clematis dioica L. – cabellos de angel
• Clematis drummondii Torr. & A.Gray – Drummond clematis
• Clematis durandii
• Clematis ispahanica Bioss
• Clematis fawcettii F.Muell.^[7]
• Clematis flammula L. – fragrant virgin's bower
• Clematis florida Thunb. – Asian clematis
• Clematis fremontii S.Watson – Fremont's leather flower
• Clematis glaucophylla Small – whiteleaf leather flower
• Clematis glycinoides DC. – headache vine^[8]
• Clematis henryi Oliv.
• Clematis hirsutissima Pursh – hairy clematis
• Clematis integrifolia L.
• Clematis × jackmanii T.Moore – Jackman's clematis
• Clematis lanuginosa Lindl. & Paxton
• Clematis lasiantha Nutt. – Pipestem Clematis
• Clematis leptophylla (F.Muell. ex Benth.) H.Eichler^[9]
• Clematis ligusticifolia Nutt. – western white clematis, hierba de chivo
• Clematis macropetala Ledeb. – downy clematis
• Clematis marmoraria Sneddon – New Zealand dwarf clematis
• Clematis microphylla DC. – small-leaved clematis^[10]
• Clematis montana Buch.-Ham. ex DC. – anemone clematis
• Clematis morefieldii Kral – Huntsville vasevine
• Clematis napaulensis DC.
• Clematis occidentalis (Hornem.) DC. – western blue virginsbower
• Clematis ochroleuca Ait. – curlyheads
• Clematis orientalis L. – Chinese clematis
• Clematis palmeri Rose – Palmer clematis
• Clematis paniculata J.F.Gmel. – puawhananga
• Clematis patens C.Morren & Decne.
• Clematis pauciflora Nutt. – ropevine clematis
• Clematis pickeringii A.Gray^[11][12]
• Clematis pitcheri Torr. & A.Gray – bluebill
• Clematis recta L. – ground clematis
• Clematis reticulata Walter – netleaf leather flower
• Clematis rhodocarpa Rose
• Clematis smilacifolia Wall.
• Clematis socialis Kral – Alabama leather flower
• Clematis stans Siebold & Zucc. – kusabotan
• Clematis tangutica (Maxim.) Korsh. – golden clematis
• Clematis terniflora DC. – leatherleaf clematis, sweet autumn clematis
• Clematis ternifolia (syn. Clematis paniculata)^[13]
• Clematis texensis Buckley – scarlet leather flower
• Clematis versicolor – manycolored leather flower
• Clematis viorna L. – vasevine, traveller's joy
• Clematis virginiana L. – devil's darning needles, Virginia bower
• Clematis vitalba L. – traveller's joy, old man's beard
• Clematis viticaulis E.Steele – Millboro leather flower
• Clematis viticella L. – Italian leather flower, purple clematis

Formerly placed here

• Akebia trifoliata (Thunb.) Koidz. (as C. trifoliata Thunb.)
• Naravelia zeylanica (L.) DC. (as C. zeylanica (L.) Poir.)^[14]

Subdivisions

One recent classification recognised 297 species of clematis, so it is not surprising that taxonomists and gardeners subdivide the genus. Several classification systems exist.

Magnus Johnson divided Clematis into 19 sections, several with subsections.^[15] Christopher Grey-Wilson divided the genus into 9 subgenera (Clematis, Cheiropsis, Flammula, Archiclematis, Campanella, Atragene, Tubulosae, Pseudanemone, Viorna), several with sections and subsections within them.^[16] Several of the subdivisions are fairly consistent between these two systems; for example, all of Grey-Wilson's subgenera are used as sections by Johnson. Alternatively, John Howell defined twelve groups: the Evergreen, Alpina, Macropetala, Montana, Rockery, Early Large-Flowered, Late Large-Flowered, Herbaceous, Viticella, Texensis, Orientalis, and Late Mixed groups.^[17]

Many of the most popular garden forms are cultivars belonging to the Viticella section of the subgenus Flammula as defined by Grey-Wilson. These larger-flowered cultivars are often used within garden designs to climb archways, pergolas, wall-mounted trellis or to grow through companion plants. These forms normally have large 12–15 cm diameter upward-facing flowers and are believed to involve crosses of C. patens, C. lanuginosa and C. viticella.^[18] Early-season, large-flowering forms such as 'Nelly Moser' tend towards the natural flowering habit of C. patens or C. lanuginosa while later-flowering forms such as ×jackmanii are nearer in habit to C. viticella.

Garden history

The wild clematis species native to China made their way into Japanese gardens by the 17th century. Japanese garden selections were the first exotic clematises to reach European gardens, in the 18th century, long before the Chinese species were identified in their native habitat at the end of the 19th century.^[19]

Cultivation

The climbing varieties are valued for their ability to scramble up walls, fences and other structures, and also to grow through other plants, such as shrubs and trees. Some can be trained along the ground to provide cover. Because of their adaptability and masses of spectacular flowers, clematis are among the most popular of all garden plants. Many choice and rare cultivars are to be had from mail order and online catalogues. Specialists regularly put on displays in national flower shows such as the Chelsea Flower Show. In theory it is possible to have a clematis in flower at any time throughout the year. Many varieties provide a second period of interest with a flush of flowers, or decorative seed heads.

They will grow in any good garden soil. The roots usually require a moist, cool substrate, while the herbage can take full sun. Some more delicate cultivars such as 'Nelly Moser' do better in light shade. Many clematis can be grown successfully in containers.^[20][21]

Pruning

The pruning regime for a cultivated clematis falls into three categories:

• Vigorous species and early-flowering hybrids do not require pruning, other than to occasionally remove tangled growth (as in C. armandii, C. montana, and C. tangutica)
• Large-flowered hybrids blooming in early summer on the previous season’s growth can be pruned lightly in the dormant season for structure
• Late-flowering hybrids which bloom on the current season’s growth can be pruned back to a pair of buds in the dormant season^[22][23]

Cultivars

see also List of Award of Garden Merit clematis

Over 80 varieties and cultivars have gained the Royal Horticultural Society’s Award of Garden Merit.^[24]

In the Atragene group are woody deciduous climbers with bell-shaped flowers in spring, produced on the last year’s growth. These include 'Markham’s Pink', a pale pink breed.^[25]

In the early large-flowered group, which flower on the last year’s growth, are:

• 'Arctic Queen' or 'Polar bear' (double white)^[26]
• 'Marie Boisselot' (white)^[27]
• 'Miss Bateman' (white with red stamens)^[28]
• 'Nelly Moser' (white with pink stripes)^[29]
• 'Niobe' (maroon)^[30]
• 'The President' (blue)^[31]

In the Clematis integrifolia group (or Integrifolia group) are non- or semi-climbing plants that flower on the current year's growth. These include the violet-pink breed 'Arabella'.^[32]

In the late large-flowered group, which flower on the current year's growth, are:

• 'Jackmanii' (purple)^[33]
• 'Polish spirit' (purple)^[34]
• 'Prince Charles' (violet)^[35]

In the Clematis montana group (or Montana group) are vigorous climbers that flower in spring, such as:

• 'Mayleen (pale pink)^[36]
• Clematis montana var. grandiflora (white)^[37]
• Clematis montana var. rubens 'Tetrarose' (rose pink with green stamens)^[38]

In the Clematis viticella group (or Viticella group) are compact deciduous climbers with small flowers produced on the current year’s growth, such as:

• 'Alba Luxurians' (white)^[39]
• 'Betty Corning' (pale lilac pink)^[40]
• 'Madame Julia Correvon' (crimson)^[41]
• 'Purpurea Plena Elegans' (purple double)^[42]

Other breeds include:

• 'Princess Diana' of the Clematis texensis or Texensis group (deep pink)^[43]
• ×triternata rubromarginata (white & purple)^[44]

Use and toxicity

The European species did not enter into the herbalists' pharmacopeia.^[45] In the American Old West the Western white clematis, Clematis ligusticifolia, was called pepper vine by early travelers and pioneers of the American Old West, who took a tip from Spanish colonials and used seeds and the acrid leaves of yerba de chivato as a pepper substitute.^[46] The entire genus contains essential oils and compounds which are extremely irritating to the skin and mucous membranes. Unlike black pepper or Capsicum, however, the compounds in clematis cause internal bleeding of the digestive tract if ingested in large amounts. C. ligusticifolia is essentially toxic. When pruning them, it's a good idea to wear gloves. Despite its toxicity, Native Americans used very small amounts of clematis as an effective treatment for migraine headaches and nervous disorders. It was also used as an effective treatment of skin infections.^[47] Clematis is also a constituent of Bach's Rescue Remedy. Leaf extracts from two Ethiopian species (Clematis longicauda steud ex A. Rich. and Clematis burgensis Engl.) are used locally to treat ear disorders and eczema. Phytochemical screening of the extracts from both of these species showed antibacterial and antifungal activity.^[48] The Extracts of these plants also possess wound healing and anti-inflammatory activities which could also be attributed to the phytoconstituents. ^[49]

Clematis has been listed as one of the 38 plants that are used to prepare Bach flower remedies,^[50] a kind of alternative medicine promoted for its effect on health. However according to Cancer Research UK, "there is no scientific evidence to prove that flower remedies can control, cure or prevent any type of disease, including cancer".^[51]

Pests and diseases

Clematis are susceptible to several pests and diseases. Clematis wilt, a stem rot caused by the fungus Phoma clematidina, causes dramatic wilting and death of whole branches, although many species are resistant to it.^[52] Other pests and diseases include powdery mildew, viruses, slugs and snails, scale insects, aphids, earwigs and green flower disease, which is usually caused by infection with a phytoplasma, a type of bacterium.^[53]

References

Further reading

• Brickell, C., Ed. Gardeners' Encyclopedia of Plants and Flowers. Dorling Kindersley. 1989.
• Toomey, M. and E. Leeds. An Illustrated Encyclopedia of Clematis. Charles Chesshire (Timber Press).

External links

Wikimedia Commons has media related to Clematis.

Wikispecies has information related to: Clematis

Wikisource has the text of the 1911 Encyclopædia Britannica article Clematis.

• American Bells - A guide to the species in subgenus Viorna
• American Clematis Society
• Clematis encyclopaedia
• Clematis on the Web
• Clematis viorna images at bioimages.vanderbilt.edu
• Clematis virginiana images at bioimages.vanderbilt.edu
• International Clematis Society
• International Registry
•  "Clematis". The American Cyclopædia. 1879.