Actually, Amanita citrina also has a volva, which is why it's so difficult to distinguish from the death cap! It's volva is an abrupt one, though, whereas the death cap has a more sac-like volva. Amanita citrina also has patches that the death cap lacks (although they can be missing), and also smells like raw potatoes.
But it's also called False Death Cap (which is a hint I guess ). He is poisonous in raw state, can be eaten after heating I think. But I would never, never, never take these. They are too easily mixed with the Death Cap.