Willowherb Blizzard

This diadem spider Araneus diadematus laboured to spin its invisible snare but made the mistake of weaving it downwind of a patch of Rosebay willowherb ....

... which made it instantly visible to insects that might otherwise have blundered into it. I watched the spider - perhaps driven by hunger after failing to catch any prey - meticulously trying to remove the cottony seeds from the web. It managed to clear the central  zone, but the outer sticky threads ....

.....collected more seeds faster than it could remove them, thanks ..

... to this large patch of willowherb upwind of the web, that released a blizzard of seeds with every puff of wind.

It's interesting to watch the willowherb seed pods open. First the four outer segments peel back like brittle banana skins, exposing ....

... a double row of seeds on each.  In still air they remain attached in rows....

.......pushed upwards on the cotton threads as they dry in the sun ....

 

.... until the slightest puff of wind whisks them away and up into the thermals. No wonder this plant is such a successful coloniser.

It's also the food plant of the elephant hawk-moth caterpillar 

Last Thursday's Guardian Country Diary was an account of pursuing this comma butterfly into a patch of willowherb.....and unleashing a blizzard of seeds in the process.