White Bladderflower

Appearance

"Araujia sericifera" is a creeping vine that can climb up to 5–7 metres high. When broken it releases a milky smelly exudate. Leaves are opposite, dark green, glossy and quite fleshy, almost triangular, with entire margins, about 10–12 centimetres long.

The twining stems bear plenty of fragrant, chalice-shaped bisexual flowers, about 2 centimetres in diameter, with five white, creamish, violet or pale pink petals. The flowers are usually pollinated by moths, butterflies and bees, but they are capable of automatic self-pollination. The structure of the flower includes a number of wedge-shaped openings that occasionally and inadvertently trap the pollinator's proboscis, leading to its death. The flowering period extends from July through September in the northern hemisphere and from November through February in the southern hemisphere.

The pear-shaped fruits are large pods, about 8–10 centimetres long. They contain numerous black seeds attached to silky hairs that enable them to be dispersed by the wind. The fruits externally resemble those of chayote or choko, hence the name "false choko".

The fast-growing vines can cover a tree canopy in two or three years, competing with the tree for light, water, and nutrients. They damage trees by this competition and by twining so tightly around their branches that it girdles them.

Naming

The genus name derives from António de Araújo e Azevedo, 1st Count of Barca, a Portuguese amateur botanist who conducted scientific studies and experiments in his own botanical garden. The species' Latin name "sericifera" means "silk-bearing" and refers to the silky hairs surrounding the seeds inside the fruits. "Araujia sericofera" is an incorrect taxonomic synonym for "Araujia sericifera".

Distribution

The plant is native to South America. It was introduced to Europe and other areas as an ornamental plant, but it is now considered a noxious weed. Nowadays its geographical distribution includes southern Europe, South Africa, North America, South America, Australia and New Zealand.

Habitat

These plants grow in wastelands with trees and hedges, in forests and in rocky places or cliffs. They prefer sunny or partially shady places, at an altitude of 0–1,800 metres above sea level.