English: Interrupted fern.
Synonyms:
Osmunda claytoniana; Osmundastrum claytonianum.
Name: interrupted describes the gap in middle of the blade left by the fertile portions after they wither and eventually fall off.
Genus: 1 species.
Region: Eastern Asia, Eastern United States, Eastern Canada.
Temporal range: Middle Triassic.
BotanyFern; forms small, dense colonies, spreading locally through its rhizome, and often forming fairy rings.
Leaves: bipinnate; 40 to 100 cm tall, 20 to 30 cm broad; blade formed of alternate segments forming an arching blade tightening to a pointed end; lower end is also slightly thinner than the rest of the frond; first segments are shorter; segments 3 to 7, short, cinnamon-colored, inserted in the middle of the length, giving the plant its name; persistent stipe bases from previous years.
Root: very large rhizome.
TaxonomyIn 2005, Claytosmunda was recognized as being somewhat different from other species in Osmunda and placed in a separate subgenus Claytosmunda. In 2016 Claytosmunda was raised to a new genus, by the Pteridophyte
Phylogeny Group classification.
Others place Claytosmunda in the genus Osmundastrum.