Clematis

From Wikipedia, the free encyclopedia

Jump to: navigation, search
Clematis
Clematis 'Nelly Moser'
Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Ranunculales
Family: Ranunculaceae
Genus: Clematis
Dill. ex L.
Species

See text.

Clematis is a genus of climbing vines with showy flowers. They are popular among gardeners, and over 200 species are known[1] with more cultivars being produced constantly. Most species are known as clematis in English, while some are also known as traveller's joy, old man's beard, leather flower, vase vine and virgin's bower, the last three being names used for North American species.

Contents

[edit] Etymology

The genus name is pronounced /ˈklɛmətɨs/,[2] from Ancient Greek klématis, a climbing plant, probably periwinkle. There are over two hundred species and cultivars, often named for their originators or particular characteristics.

[edit] Botany

The genus is composed of mostly vigorous, woody, climbing vines technically called lianas. The woody stems are quite fragile until several years old.[1] Leaves are usually divided into leaflets, with leafstalks that twist and curl around supporting structures to anchor the plant as it climbs.[1] Some species are shrubby, and some others are herbaceous perennial plants. The cool temperate species are deciduous, but many of the warmer climate species are evergreen. They grow best when their roots are shaded but their tops are in full sun. They are generally acid-intolerant calciphytes that grow on limestone and other basic soils.

Though they are famous as flowering plants, the clustered true flowers are in fact tiny; the showy parts are actually sepals that resemble colorful flower petals.[1] The blossoms and sepals eventually fall away leaving fluffy clusters of seeds with tails.[1] The timing and location of flowers varies; spring-blooming clematis flower on the previous year's stems, summer/fall blooming clematis bloom only on the ends of new stems, and twice-flowering clematis do both at the respective times.[1]

Clematis species are found throughout the temperate regions of both hemispheres, and also in mountains in the tropics. Clematis leaves are food for the caterpillars of some Lepidoptera species, including the Willow Beauty (Peribatodes rhomboidaria).

[edit] Use and toxicity

Clematis was called pepper vine by early travelers and pioneers of the American Old West and used as a pepper substitute to spice up food since true black pepper (Piper nigrum) was a costly and rarely obtainable spice. 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. The plants are essentially toxic. 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.[3]

[edit] 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"
Closeup of a Clematis flower
Macro of seeds

A partial list of species:

[edit] 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.[4] 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.[5] 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.[6]

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 12-15cm diameter upward-facing flowers and are believed to involve crosses of C. patens, C. lanuginosa and C. viticella.[7] Early-season, large-flowering forms (eg. "Nelly Moser") tend towards the natural flowering habit of C. patens or C. lanuginosa while later-flowering forms (eg. x jackmanii) are nearer in habit to C. viticella.

[edit] References

  1. ^ a b c d e f Bender, Steve, ed (January 2004). "Clematis". The Southern Living Garden Book (2nd ed.). Birmingham, Alabama: Oxmoor House. pp. 250-2. ISBN 0-376-03910-8. 
  2. ^ Sunset Western Garden Book. 1995. pp. 606–7. 
  3. ^ Edible and Medicinal Plants of the West. ISBN 0-87842-359-1. 
  4. ^ Johnson, Magnus (2001). The Genus Clematis. Magnus Johnson Plantskola AB. 
  5. ^ Grey-Wilson, Christopher (2000). Clematis: The Genus: A Comprehensive Guide for Gardeners, Horticulturists and Botanists. Timber Press. 
  6. ^ Howell's 12 Groups
  7. ^ Evison, Raymond J. (1998). The Gardener's Guide to Growing Clematis. Timber Press/David and Charles. 

[edit] External links

Search Wikimedia Commons Wikimedia Commons has media related to: Clematis
Retrieved from "http://en.wikipedia.org/wiki/Clematis"