Sky trees?

Decided on a walk this afternoon to try and reawaken my senses and disperse the clouds. Fortunately it only needs a quick hop across the road and I'm on the canal and in my green world.

Of various interesting things seen, this was the best. Can anyone help? Water horsetail?

*EDIT

First thing spotted was a gorgeous Iris pseudacorus (flag Iris). Then it was oil on water (where the oil was from I have no idea but I reckon it my have popped up from the sediment of the canal). Next it was this absolute nutcase. He almost walked on water to get to me and I was sad I had nowt to feed him. Going back tomorrow to oblige if he's there. Finally a nondescript yellow thing. Utterly unremarkable until you look at the wee insect sheltering in the lower bit of the flower.

Of course the mini-trees in question are Hippuris vulgaris. Silly me.