A genus of 35 species, perennial herbs, nearly cosmopolitan, but primarily temperate and concentrated in North America and e. Asia. Botrychium as traditionally circumscribed to include Botrypus and Sceptridium is very heterogeneous (Hauk, Parks, & Chase 2003); I have here accepted the arguments of Hauk (1996), Hauk, Parks, & Chase (2003), PPG I (2016), and others recommending recognition of the anciently divergent and molecularly and morphologically distinctive segregates as genera. Dauphin, Vieu, and Grant (2014) verify the controversial naming of many cryptic and semi-cryptic species in Botrychium by W.H. Wagner and others in recent decades.
ID notes:Botrychium has sterile leaf blades with a division pattern that is pinnate, the blade is thus elongate rather than the equilaterally triangular or pentagonal outline of the ternately divided blades of Sceptridium and Botrypus.
Ref: Hauk (1996); Hauk, Parks, & Chase (2003); PPG I (2016); Stensvold & Farrar (2017); Wagner & Wagner (1993) In Flora of North America Editorial Committee (1993b); Wagner In Kramer & Green (1990); Williams, Farrar, & Henson (2016). Show full citations.