Non-native explosive specialist found by Thames

For the first time, I saw a patch of Impatiens glandulifera, aka Himalayan Balsam, aka Policeman's Helmet, growing near the river in our village.

This is a very invasive species which will no doubt soon be muscling out less pushy home-grown plants. I read in my Clapham, Tutin and Warburg (1959 edition) that this plant is "locally common in N and W England and Wales, less so in S E England, Scotland and Ireland, but increasing.

The exciting thing about this flower is its exploding seed capsules, which really are comulsive popping material, a rival for bubble wrap. Catch a pod at its ripest, and when the sides are pressed ..... well, CT&W describe it thus: "loculicidal capsule with the valves dehiscing elastically and coiling". No wonder its march across Britain is so phenomenal.