The Cinnamon Fern is a conspicuous and an easily recognizable fern that thrives in Tennessee. Like all ferns in this family, it has dimorphic fronds. The sterile fronds are large and green with highly dissected pinna. There is also an important diagnostic feature on the underside of these fronds, where the pinna meet the stipe there will a tiny patch of what looks like hair (colloquially but cleverly called "hairy pits"). The fertile fronds are quite different; they are vertical stipes with the cinnamon brown pinna helically wrapped around the stipe.