The fronds of cinnamon fern occur in groups, rising from a shallow, black rootstock. Fertile fronds appear first as silvery, furry fiddleheads, ultimately becoming stiff, erect, and covered with specialized pinnae, which turn their upper portions into a thick spike of fruit dots – turning from green to chocolate brown. Sterile fronds bend outwards forming a vase-shaped circle enclosing the cinnamon fronds. The fern can reach a height of 6 ft. The contrasting stature of fertile and infertile fronds can make for dramatic accents in a landscape.
