It's the same in the UK.Rhubarb (at least in the U.S.) is the one with the bright red stalks. Yours looks like something completely different. I googled rheum and it didn't show anything like yours. It might be a plant we just don't have here.
I agree with Donny. This sort of Rheum seems to grow wild, but ours is cultivated. If you wanted to talk about it you'd have to explain that it's a sort of rhubarb known as 'Syrian rhubarb', apparently. Its name means 'blackcurrant rhubarb'. It might be in the rhubarb family but it's very different from our idea of rhubarb.My guess, from reading the Wikipedia article in the link, is that it's a variety of rheum that isn't commonly grown or found in the UK.