A family of 6 genera and about 18 species. Our three species have traditionally been all placed in Osmunda, but PPG I (2016) and others show that Osmunda s.l. includes ancient, divergent clades with ages of 100-250 million years, and also with great morphological divergence, warranting generic recognition (Schneider et al. 2015, PPG I 2016). We here follow PPG I (2016) in recognizing three genera in our area: Osmunda, Osmundastrum, and Claytosmunda.
ID notes: Osmundaceae are large, coarse, clump-forming ferns from thick rhizomes; the rhizomes, densely clad with old leaf bases, often form large mounds on the ground surface, especially noticeable after fires. Osmunda spectabilis is a wetland species and Osmundastrum cinnamomeum occurs primarily in wetlands, while Claytosmunda claytoniana is usually in moist to dry uplands, but can occur in wetlands.
Ref: Bomfleur, Grimm, & McLoughlin (2015); Bomfleur, Grimm, & McLoughlin (2017); Kramer & Green (1990); Lellinger (1985); Metzgar et al. (2008); PPG I (2016); Schneider et al. (2015); Sylvestre, Costa, & Arana (2022); Whetstone & Atkinson (1993) In Flora of North America Editorial Committee (1993b); Yatabe, Nishida, and Murakami (1999). Show full citations.