Kingdom: Plantae
Division: Pteridophyta (Filicophyta)
Class: Osmundopsida
Order: Osmundales
Family: Osmundaceae
Genus: Osmunda

Osmunda cinnamomea

Common names: cinnamon fern, flowering fern

(Drawing from How to Know the Ferns by Frances Parsons)

The cinnamon fern is a common fern in swampy areas in eastern North America. It is found in southern Florida as well as in New England. In some areas, especially in the Appalachian mountains, it grows in huge Osmunda bogs where it is the principal understory plant, often with fronds four to five feet tall, and forming large, fibrous hummocks. Often the royal fern, O. regalis, will be found growing with it.

This fern has firm, pinnate-pinnatifid fronds, up to 1.5 meters, or about five feet, tall, and the spore is born on separate, highly-modified fronds on which the lamina is entirely replaced with sporangia. These arise in early spring and turn a bright golden brown, then a dark cinnamon brown, then wilt. The rootstock usually forms at least a small hummock above the ground, with wiry, fibrous dark brown, almost black, roots.

This plant is often confused with the interrupted fern, O. claytoniana, and the Virginia chain fern, Woodwardia virginica. However, the interrupted fern usually grows in moist hillside pockets, and the spore areas are in the middle of the fronds, not on separate fronds, and the chain fern has sori on the backs of the fronds and has a slender, running rhizome and the fronds are often emerging from the water rather than the rootstock emerging from the water.

The cinnamon fern is easy to grow in the garden and can make a handsome specimen, as well as being attractive when sporing. It is commonly available from nurseries.

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This page was last revised on 11-10-1997.