Where Does Cinnamon Come From?

I have a question about cinnamon, does it come from the bark of a tree, or does it come from a fern?

The most common and best variety of cinnamon is the bark from the tropical cinnamon tree, Cinnamomum zeylanicum. The cassia cinnamon, Cinnamomum cassia, is similar, but the bark pieces are coarser in size and the flavour is considered somewhat inferior. Both are used as "cinnamom" spice.
The cinnamon fern, Osmunda cinnamomea, is completely different. It is a native of North, Central and South America, and of parts of Asia. It is called cinnamon fern because its spore cases have a cinnamon colour, not because the plant has any cinnamon flavour or can be used as a spice. It has medicinal properties although it is not commonly used. According to John Lust in his "The Herb Book" (available from Richters), it is used like other medicinal ferns, but is not as effective. "It can be boiled in milk to produce mucilage which is helpful for diarrhea" according to Lust.