Wednesday, August 6, 2008

An explosive fellow.


Policeman’s helmet, Impatiens glandulifera

Among the exotica growing at the Great Blue Heron Nature Reserve in Chilliwack is Policeman’s helmet, Impatiens glandulifera, a member of the Balsaminaceae. The flowers have five petals (two fused), three sepals (two fused) and five stamens with fused filaments. The flower shape, as seen from the side, suggests a policeman’s (English Bobby’s) helmet.

This plant can grow to three metres high, especially in shady spots. It thrives in wet forests, river banks, lake edges and other damp habitats.

Its fruits are oblong, five-chambered capsules that when touched open explosively, splitting along the seams of the fused stamens. Great fun! Seeds can shoot up to 20 feet away, and a plant can produce several hundred.

Policeman’s helmet is native to India and the western Himalayan region. It was brought to The Royal Botanic Gardens, Kew, in 1839, and didn’t take long to become naturalized throughout the United Kingdom, much like the story of the Giant Hogweed and no doubt other species. It has become established in 18 European countries, and, in North America, in parts of Western Washington State and the lower Fraser River Valley in British Columbia.

One notable site in the Greater Vancouver Area is Burnaby Lake, where this plant battles for space with fellow-aliens Himalayan blackberry and purple loosestrife.

When confronted with a Policeman’s helmet with plump ripe capsules, do your best not to pop them. Warning: They are near-irresistible.

Just one?

No, you won’t be able to stop.

Puh-leeze?

Well, okay, but just one.

Pop!

Pop! Pop! Pop! Pop! Pop! etc.

Impatiens glandulifera – Nature’s bubble wrap.

Tiny, unripe seed capsules are visible at the top of this plant.

3 comments:

Cicero Sings said...

They really are fun to pop!

BerryBird said...

Are the seeds that scatter when you pop the capsule edible like with I. capensis and I. pallida, native to northeastern North America? Because if you are hungry, the best strategy is to wrap you fist around the capsule so it explodes in your hand. They taste a bit walnutty.

Hugh said...

I don't know about their edibility, but I woudn't be surprised. (I'll let someone else do the test.)