American wisteria, the star of climbers

What do green beans and the elegant wisteria that adorns the porches of Desperate Housewives homes have in common? They both belong to the Fabaceae family. Native to the east coast of the United States, American wisteria or Wisteria frutescens is no longer confined to American gardens. It can now be found all over the world.

Wisteria grows up to six meters high and three meters wide. This flowering climber grows by wrapping its vines around its support. In the absence of a pergola or trellis on which to cling, Wisteria frutescens grows on its woody stem, like a small tree.

American wisteria foliage is deciduous. It turns golden yellow in autumn before falling. In spring and summer, it turns a glossy dark green. It has alternate leaves. Each leaf has an odd number of leaflets, between nine and fifteen, and two stipules at its base. Oval and lanceolate, they are arranged in opposite pairs. Glabrous on the upper surface, they are covered with down on the underside.

American wisteria flowers after chinese Glycine and japanese Glycine. Flowering occurs from May to July and continues, more discreetly, until September. Flowers appear in clusters from 15 to 25 centimetres long. Lilac or blue in color, they give off a slightly spicy fragrance.

In autumn, the fruit replaces the inflorescence. It's a flat, brown pod five to ten centimeters long.

If you travel to the United States, you may be offered the chance to taste Wisteria frutescens flowers. They're sometimes eaten raw, in salads, or fried, in fritters. But tasting them is not always a good idea. American wisteria remains a toxic plant. Its seeds can cause digestive problems in humans and animals. In contact with the eyes, its juice causes irritation.