Clematis
Clematis is a genus of about 380 species within the buttercup family, Ranunculaceae. Their garden hybrids and cultivars have been popular among gardeners, beginning with Clematis 'Jackmanii', a garden staple since 1862. More cultivars are being produced constantly, mainly of Chinese and Japanese origin.
Species names
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. terniflora, C. virginiana, and C. viticella;old man's beard, applied to several with prominent seedheads;leather flower for those with fleshy petals; or vase vine for the North American Clematis viorna.Etymology
The genus name Clematis is from Ancient Greek κληματίς : clēmatís, from κλήμα : klḗma – 'twig, sprout, tendril'.Botany
The genus is composed of mostly vigorous, woody, climbing vines / lianas. The woody stems are quite fragile until several years old. Leaves are opposite and divided into leaflets and leafstalks that twist and curl around supporting structures to anchor the plant as it climbs. 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.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.
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.
Taxonomy
The genus Clematis was first published by Carl Linnaeus in Species Plantarum in 1753, the first species listed being Clematis viticella. The genus name long pre-dates Linnaeus. It was used in Classical Greek for various climbing plants, and is based on κλήμα, meaning vine or tendril.''Archiclematis'' and ''Naravelia''
Some morphologically distinctive taxa lacking the combination of characters defining Clematis were formerly segregated as the genera Archiclematis and Naravelia. DNA sequence studies have found that these two genera are deeply nested in Clematis, the morphological characters they were erected on being either reversals or misinterpretations, and that consequently the genera should be reduced to the synonymy of Clematis. Naravelia is a monophyletic group within Clematis.Species to be transferred include:Clematis alternata syn. Archiclematis alternataClematis antonii, syn. Naravelia antoniiClematis dasyoneura, syn. Naravelia dasyoneuraClematis horripilata, syn. Naravelia laurifoliaClematis zeylanica, syn. ''Naravelia zeylanica''
Species
A partial list of species:Clematis addisonii Britt. – Addison's leather flowerClematis akebioides H.J.VeitchClematis albicoma Wherry – whitehair leather flowerClematis alpina Mill. – alpine clematisClematis aristata – Australian clematisClematis armandii – Armand clematisClematis baldwinii Torr. & A.Gray – pine hyacinthClematis bigelovii Torr. – Bigelow clematisClematis brachiata Thunb. – traveller's joyClematis campaniflora Brot. – Portuguese clematisClematis catesbyana – satin curlsClematis chinensis Osbeck – wei ling xian in Chinese Clematis chrysocoma Franch. – gold wool clematisClematis cirrhosa L. – includes the 'Freckles', 'Wisley Cream', and 'Jingle Bells' cultivars- * Clematis cirrhosa v. balearica Clematis coactilis Keener – Virginia whitehair leather flowerClematis columbiana Torr. & A.Gray – British Columbia virgin's bowerClematis crispa L. – swamp leather flowerClematis cunninghamiiClematis dioica L. – cabellos de angelClematis drummondii Torr. & A.Gray – Drummond clematisClematis durandiiClematis fawcettii Clematis flammula L. – fragrant virgin's bowerClematis florida Thunb. – Asian clematisClematis foetida Raoul – New Zealand clematisClematis fremontii S.Watson – Fremont's leather flowerClematis glaucophylla Small – whiteleaf leather flowerClematis glycinoides – headache vineClematis gouriana – Indian traveller's joyClematis henryi Oliv.Clematis hirsutissima Pursh – hairy clematisClematis hedysarifolia Clematis integrifolia L.Clematis ispahanica BiossClematis × jackmanii T.Moore – Jackman's clematisClematis koreana Kom. – Korean clematisClematis lanuginosa Lindl. & PaxtonClematis lasiantha Nutt. – pipestem clematisClematis leptophylla Clematis ligusticifolia Nutt. – western white clematis, hierba de chivoClematis linearifolia Steud.Clematis macropetala Ledeb. – downy clematisClematis mandshuricaClematis marmoraria Sneddon – New Zealand dwarf clematisClematis microphylla – small-leaved clematisClematis montana Buch.-Ham. ex DC. – anemone clematisClematis morefieldii Kral – Huntsville vasevineClematis napaulensis DC.Clematis occidentalis DC. – western blue virginsbowerClematis ochroleuca Ait. – curlyheadsClematis orientalis L. – Chinese clematisClematis palmeri Rose – Palmer clematisClematis paniculata J.F.Gmel. – puawhanangaClematis patens C.Morren & Decne.Clematis pauciflora Nutt. – ropevine clematisClematis pickeringii Clematis pitcheri Torr. & A.Gray – bluebillClematis pubescens Hügel ex Endl. – common clematisClematis recta L. – ground clematisClematis reticulata Walter – netleaf leather flowerClematis rhodocarpa RoseClematis smilacifolia Wall.Clematis socialis Kral – Alabama leather flowerClematis stans Siebold & Zucc. – kusabotanClematis tangutica Korsh. – golden clematisClematis terniflora DC. – sweet autumn clematisClematis texensis Buckley – scarlet leather flowerClematis urophyllaClematis versicolor – manycolored leather flowerClematis verticillaris – purple virgins bowerClematis viorna L. – vasevine, traveller's joyClematis virginiana L. – devil's darning needles, Virginia bowerClematis viridiflora Bertol.Clematis vitalba L. – traveller's joy, old man's beardClematis viticaulis E.Steele – Millboro leather flowerClematis viticella L. – Italian leather flower, purple clematis
Formerly placed here
Akebia trifoliata Koidz.Subdivisions
One recent classification recognised 297 species of clematis. Consequently, taxonomists and gardeners subdivide the genus. Several classification systems exist.Magnus Johnson divided Clematis into 19 sections, several with subsections. Christopher Grey-Wilson divided the genus into 9 subgenera, several with sections and subsections within them. 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.
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, or wall-mounted trellises, 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. 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
Clematis patens C.Morren et Decne., native to Japan, was introduced to Europe in 1836 by Philipp Franz Balthasar von Siebold. Today, it is the most frequently used species for developing large-flowered cultivars.The wild Clematis species, such as Clematis florida, native to China had also made their way into Japanese gardens by the 17th century. These species were also brought to Europe through Japan.
Japanese garden selections, mostly cultivated in Edo Period using species that are native to Japan or China, 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.
After it arrived in Europe, it acquired several meanings during the Victorian era, famous for its nuanced flower symbolism. It came to symbolize both mental beauty and art as well as poverty.
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.
Pruning
Different varieties and cultivars require varied pruning regimes from no pruning to heavy pruning annually. 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
- 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
Cultivars
Over 80 varieties and cultivars have gained the Royal Horticultural Society's Award of Garden Merit clematis|Award of Garden Merit].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.
In the early large-flowered group, which flower on the last year's growth, are:
- 'Arctic Queen' or 'Polar bear'
- 'Clematis Josephine' or 'Clematis Evijohill'
- 'Marie Boisselot'
- 'Miss Bateman'
- 'Nelly Moser'
- 'Niobe'
- 'The President'
In the late large-flowered group, which flower on the current year's growth, are:
- 'Jackmanii'
- 'Polish spirit'
- 'Prince Charles'
- 'Mayleen Clematis montana var. grandiflora Clematis montana var. rubens 'Tetrarose'
- 'Alba Luxurians'
- 'Betty Corning'
- 'Madame Julia Correvon'
- 'Purpurea Plena Elegans'
- 'Princess Diana' of the Clematis texensis or Texensis group
- ×triternata rubromarginata
Horticultural classification
This follows the classification adopted by V. Matthews in The International Clematis Register and Checklist 2002, except that C. ispahanica, now considered to have been included in error, has been omitted from the list of parent species in Tangutica Group.- Small-flowered Division: Flowers 2–12 cm across
- * Armandii Group: Cultivars belonging to, or derived from, species classified in subsection Meyenianae M. Johnson, mainly C. armandii.
- * Atragene Group: Cultivars belonging to, or derived from, species classified in subgenus Atragene Torrey & A. Gray, such as C. alpina, C. chiisanensis, C. fauriei, C. koreana, C. macropetala, C. ochotensis, C. sibirica, C. turkestanica. The former Alpina Group and Macropetala Group are included here. Historically, the Alpina Group was used for single-flowered cultivars, and double-flowered cultivars were assigned to the Macropetala Group.
- * Cirrhosa Group: Cultivars belonging to, or derived mainly from, C. cirrhosa.
- * Flammula Group: Cultivars with at least one parent belonging to, or derived from, species classified in section Flammula DC., such as C. angustifolia, C. flammula, C. recta, C. terniflora.
- * Forsteri Group: Cultivars belonging to, or derived from, species classified in section Novae-zeelandiae M. Johnson such as C. australis, C. foetida, C. forsteri, C. marata, C. marmoraria, C. paniculata, C. petriei.
- * Heracleifolia Group: Cultivars with at least one parent belonging to, or derived from, species classified in subgenus Tubulosa Grey-Wilson, such as C. heracleifolia, C. stans, C. tubulosa.
- * Integrifolia Group: Cultivars belonging to, or derived mainly from, C. integrifolia. Includes the Diversifolia Group.
- * Montana Group: Cultivars belonging to, or derived from, species classified in section Montanae Grey-Wilson such as C. chrysocoma, C. montana, C. spooneri.
- * Tangutica Group: Cultivars with at least one parent belonging to, or derived from, species classified in section Meclatis Baill., such as C. intricata, C. ladakhiana, C. orientalis, C. serratifolia, C. tangutica, C. tibetana. This Group has also been known as the Orientalis Group.
- * Texensis Group: Cultivars derived from C. texensis crossed with representatives from either of the Large-flowered Groups.
- * Viorna Group: Cultivars with at least one parent belonging to, or derived from, species classified in section Viorna A. Gray, such as C. crispa, C. fusca, C. ianthina, C. pitcheri, C. reticulata, C. texensis, C. viorna. Cultivars assigned to Texensis Group, and cultivars with C. integrifolia in their parentage, are excluded.
- * Vitalba Group: Cultivars with at least one parent belonging to, or derived from, species classified in section Clematis L., such as C. ligusticifolia, C. potaninii, C. vitalba, C. virginiana.
- * Viticella Group: Cultivars with at least one parent mainly derived from C. viticella. Excludes hybrids between C. integrifolia and C. viticella: see Integrifolia Group.
- Large-flowered Division: Flowers 10–22 cm across, usually flat.
- * Early Large-flowered Group: Comprises the former Patens Group and Fortunei Group. Cultivars of the Patens Group were derived mainly from C. patens, either directly or indirectly. They were characterized by producing flowers in spring on the previous year's wood, and often again in summer or early autumn on the current year's growth. The former Fortunei Group comprised cultivars with double or semi-double flowers that were produced on the previous year's growth in spring. Hybridization has made it impossible to keep the original Groups separate: there are a number of cultivars that produce both single and double flowers, or that only produce semi-double or double flowers under certain conditions.
- * Late Large-flowered Group: Comprises the former Lanuginosa Group and Jackmanii Group. Cultivars of the Lanuginosa Group were derived mainly from C. lanuginosa, either directly or indirectly. The Jackmanii Group covered cultivars produced from a cross between C. viticella and a member of the Patens Group. Both Groups produce their flowers on the current year's growth in summer and autumn. It is often impossible to say whether a cultivar belongs to the Lanuginosa Group or to the Jackmanii Group, due to hybridization and/or lack of information on the parentage, so it is not possible to maintain these Groups.
Use and toxicity
The European species did not enter into the herbalists' pharmacopeia. In the American Old West, the Western white clematis, Clematis ligusticifolia, was called pepper vine by early travelers and pioneers, who took a tip from Spanish colonials and used seeds and the acrid leaves of yerba de chivato as a pepper substitute. 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 is 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. Clematis is also a constituent of Bach's Rescue Remedy. Leaf extracts from two Ethiopian species are used locally to treat ear disorders and eczema. Phytochemical screening of the extracts from both of these species showed antibacterial and antifungal activity. The extracts of these plants also possess wound healing and anti-inflammatory activities which could also be attributed to the phytoconstituents.Clematis has been listed as one of the 38 plants used to prepare Bach flower remedies, 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".