Translations:AY Honors/Ferns/Answer Key/23/en

Osmunda claytoniana

Interrupted Fern (Osmunda claytoniana)

Where found: Osmunda claytoniana is native to eastern North America and eastern Asia. In eastern North America it occurs from southern Manitoba, Ontario, Quebec (up to the tree line), east to Newfoundland and south through the Appalachian mountains down to Georgia and west to the Mississippi River. In Asia, it is found in the Himalaya, southern China, Japan, Korea, and Taiwan.

Description: The fronds are bipinnate, 40-100 cm tall and 20-30 cm broad, the blade formed of alternate segments forming an arching blade tightening to a pointed end. The lower end is also slightly thinner than the rest of the frond because the first segments are shorter. Three to seven short, cinnamon-colored fertile segments are inserted in the middle of the length, giving the plant its name. In their absence, the plant in all its stages is extremely similar to Osmunda cinnamomea (Cinnamon Fern). To distinguish them, look at the base of the segments; where O. cinnamomea has typical felt-like hairs, the few hairs present on O. claytoniana are extremely short, usually requiring a magnifying glass to see well.