Himalayan Balsam

Scientific Names:

Impatiens glandulifera
Other names: Policeman's helmet, Indian Touch-Me-Not, Ornamental Jewelweed, Pink Peril, Poor Man's Orchid

Description and Info:

A large succulent, annual introduced in 1839 to Kew Gardens as a greenhouse plant. It then escaped to the wild, now naturalised in the British Isles and many other non-native countries. it is very invasive and should be removed when found. It is in the same genera as the colourful, bedding Impatiens or Busy-lizzies but grows much taller (up to 2 metres high). Preferred sites are moist areas usually along river banks but it colonises many other areas. Dense stands suffocate other plants so when it dies away in the winter, river banks are left bare and more liable to erosion.
The sap can be used to sooth the rash caused by Poison Ivy and the stems can be eaten after boiling. A yellow dye can be extracted from the whole plant.

The hollow, succulent stems have a purple tinge and are smooth or glabrous. The serrated, pointed leaves are arranged in pairs or three to a node; they are mid green and about 12 to 16cm long.

The flowers vary from pale pink to purple and appear from June to October. The shape resembles an English policeman's helmet, leading to one of the common names. They produce copious amounts of nectar and are thought to draw pollinating insects in preference to native plants so reducing pollination of the latter.

A single plant can set about 800 seeds; 12 to 14 weeks after flowering. The seed capsules react to the slightest disturbance causing the five segments to split along their length, curl up and twist explosively, projecting the contents up to 7 metres away. (This "impatient" release of the seed gives it its approved name, Impatiens).

The black, spherical seeds are about 2 to 3mm across and remain viable for about 2 years, requiring cold stratification for germination which occurs in February or March. They are buoyant and can travel along waterways to infest new areas, even germinating under water.