What is the difference between anenome and anemone?

An anemone is a plant in the buttercup family, or a marine invertebrate, the sea anemone. There's no such thing as an "anenome", as my spell checker is telling me right now! It's just a common mispronunciation, often by people who should know better, including Monty Halls narrating his documentary about the Great Barrier Reef I've just been watching on BBC2.