(Ranunculus fluviatile). Since he put the question I have been wondering about this. Yesterday evening, a wet, cold evening, I browsed the Internet in pursuit of the answer. The nearest I came seemed to be in a paper by the French ecologist, Georges Erome, who had done a search through the literature for species of plant that beavers consume. The list went down only to the level of the genus, so far as herbaceous plants went. One author had recorded beaver as consuming members of the genus Ranunculus: a bit disappointing really.
My search had been spurred on my Heidi Perryman who, sharp witted lady that she is, remembered that I had mentioned Water Crowfoot here.
After the wonderful warm spell of last week, the weather has reverted to cold and wet, so the flowers were closed, but here is a photograph. The grass has been nibbled a bit, but I could see no sign of grazing on the Water Crowfoot. This area has now been added to the formal Water Margin and is enclosed by a fence to protect from the grazing of livestock.
The lower photograph has a lot of Starwort (Callitriche palustris) in it. This was a species that received more mention in the Erome paper than Water Crowfoot.
At Freising in 2006, Alexandr Bobrov exhibited a poster in which the species of plant consumed by beavers in the Upper Volga were listed. I must find a copy of that.
I should be surprised if beavers did not eat Water Crowfoot, but probably in small quantities: something like 0.02% of their rations - a nibble here, a nibble there.