Osmunda claytoniana is a fern from the end of a stout, fibrous rhizome.
Leaves in a large rosette, to 1.2 m tall, to 30 cm wide, once pinnate, leaflets (pinnae) deeply lobed, lobes shorter and appearing coarser than those of O. cinnamomea, tips blunt;
Spore cases on fertile pinnae 1-5 pairs, along middle part of leaf stalk, 6 x 2 cm, much smaller than green, pinnae above and below, red-brown, soon withering. Not much used by wildlife.
Wetland status: FAC.
Frequency in NYC: Occasional.
Origin: Native to NYC.
Habitat: Moist upland woods, sub-acid to neutral soil. Usually distinctly upland of O. cinnamomea populations.
Notes: A host of the white-spored fir rust Uredinopsis osmundae (a fir-fern rust, Basidiomycotina) (Sinclair et al. 1987; Bailey et al. 1976).*Not actually flowering. A common name for the family Osmundaceae or ferns with showy sporangia.