Dennstaedtiaceae

1. Blades usually broadly triangular, divide into three ± equal segments (ternate); sori (often absent) continuous along blade margins.

Pteridium

1. Blades narrowly to broadly ovate, pinnate, with a main axis; sori distinct, not continuous along margins.

Dennstaedtia

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 12, 2017. http://www.michiganflora.net/family.aspx?id=Dennstaedtiaceae.