I saw this at Howick hall gardens in Northumberland last weekend.
Can anyone ID this arisaema?
It looks very much like A. triphyllum. They do vary in colour, the leaves from what I can see are typical, having three leaflets per stem.
I concur, probably triphyllum, the most common here in North America, one of our two native varieties. (East coast, the other being A. Draconitum or something like that) Though it could possibly be of Japanese origin, I have seen some similar spathes on different forms of A. speciosum, but triphyllum is the best guess.