Friday, August 30, 2013

Botanical artillery...

Cranesbills are wild flowers with a particularly violent method of dispersing their seeds, that involves a catapult mechanism and is particularly well developed in bloody cranesbill Geranium sanguineum.

Cranesbills belong to the genus Geranium, a name that's derived from the Greek word geranos, meaning 'crane' (the bird, not the mechanical device) and nicely describes the central axis of the fruit, which resembles a crane's beak.




There are five egg shaped seed containers at the base of that long beak, which is formed from five long strips of plant tissue that are firmly attached to the tip of the beak and develop tremendous internal tensions as they dry out. They are botanical springs and when their inner tensions reach a critical point they break free at the base and curl away from it with enormous force......


































.... so that they curl upwards with the egg-shaped containers attached, hurling out the seed which lies in each container, in much the same way as those dog ball throwers that dog walkers use. After the seeds have been dispersed this elegant candelabra-like structure is left behind.

Bloody cranesbill is the official county wild flower of Northumberland.




2 comments:

  1. Hi Phil, haven't been here for a while. That is a very informative post for a very beautiful unusual plant. Best regards!

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  2. Thanks Andrea, it's one of my favourites and grows along the coast here (and in my garden!). with best wishes, Phil

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