Indian balsam

Indian balsam (Impatiens glandulifera) is a plant that grows wild in several parts of the United Kingdom but it is no means a native plant, as might be gathered from its name. It is known that it first reached the UK from India in 1839, introduced as a greenhouse plant, but seeds escaped and led to wild populations getting a foothold. Where it occurs, Indian balsam does very well on waste ground and on river banks.

Indian balsam can grow as high as 80 inches (200 centimetres). It has sturdy ribbed stems that bear pointed leaves growing in groups of three and pointing in different directions. It produces large purplish flowers from July to October.

The pear-shaped fruiting capsules release ripe seeds by springing back their sides and throwing the seed a considerable distance. This can happen when the plant is touched by a passing person or animal.

Pollination is ensured by the shape of the flower which closes completely around any bee that visits to takes its nectar, although the trapping is only temporary. The insect has no choice but to touch both stamen (male) and pistil (female) as it moves from flower to flower and therefore to transfer pollen.

© John Welford