Wysteria Tree

La glycine est un genre de plantes à fleurs de la famille des légumineuses, Fabaceae .....

Wisteria is a genus of flowering plants in the legume family, Fabaceae (Leguminosae), that includes ten species of woody climbing bines that are native to China, Korea, Japan, and the Eastern United States. Some species are popular ornamental plants. An aquatic flowering plant with the common name wisteria or 'water wisteria' is in fact Hygrophila difformis, in the family Acanthaceae.

Taxonomy

The botanist Thomas Nuttall said he named the genus Wisteria in memory of Dr Caspar Wistar (1761–1818).Questioned about the spelling later, Nuttall said it was for "euphony," but his biographer speculated that it may have something to do with Nuttall's friend Charles Jones Wister, Sr., of Grumblethorpe, the grandson of the merchant John Wister.

Some Philadelphia sources state that the plant is named after Wister.As the spelling is apparently deliberate, there is no justification for changing the genus name under the International Code of Botanical Nomenclature.However, some spell the plant's common name "wistaria"

Genetic analysis shows Callerya, Afgekia and Wisteria to be each other's closest relatives and quite distinct from other members of the tribe Millettieae. Both have eight chromosomes.

Species

The following is a list of accepted Wisteria species:

Wisteria brachybotrys Siebold & Zucc. – Silky wisteria

Wisteria brevidentata Rehder

Wisteria floribunda (Willd.) DC. – Japanese wisteria

Wisteria frutescens (L.) Poir. – American wisteria

Wisteria macrostachya (Torr. & Gray) Nutt. ex BL Robins. & Fern. – Kentucky wisteria

Wisteria sinensis (Sims) DC. – Chinese wisteria

Wisteria venusta Rehder & Wils (or W. ventusa Rehder & Wils.)

Wisteria villosa Rehder

Wisterias climb by twining their stems around any available support. W. floribunda (Japanese wisteria) twines clockwise when viewed from above, while W. sinensis twines counterclockwise. This is an aid in identifying the two most common species of wisteria. They can climb as high as 20 m (66 ft) above the ground and spread out 10 m (33 ft) laterally. The world's largest known wisteria is in Sierra Madre, California, measuring more than 1 acre (0.40 ha) in size and weighing 250 tons. Planted in 1894, it is of the 'Chinese lavender' variety.

The leaves are alternate, 15 to 35 cm long, pinnate, with 9 to 19 leaflets. The flowers are produced in pendulous racemes 10 to 80 cm long, similar to those of the genus Laburnum, but are purple, violet, pink or white. There is no yellow on the leaves. Flowering is in spring (just before or as the leaves open) in some Asian species, and in mid to late summer in the American species and W. japonica. The flowers of some species are fragrant, most notably W. sinensis. Wisteria species are used as food plants by the larvae of some Lepidoptera species including brown-tail.

The seeds are produced in pods similar to those of Laburnum, and, like the seeds of that genus, are poisonous. All parts of the plant contain a saponin called wisterin, which is toxic if ingested, and may cause dizziness, confusion, speech problems, nausea, vomiting, stomach pains, diarrhea and collapse. There is debate over whether the concentration outside of the seeds is sufficient to cause poisoning. Wisteria seeds have caused poisoning in children and pets of many countries, producing mild to severe gastroenteritis and other effects.