Osmunda -Key to the Genus


Sterile fronds completely bipinnate, the pinnules well separated (usually over 3 mm apart) along the rachis of the pinna; fertile fronds with the fertile pinnae terminal, sterile pinnae below.


Sterile fronds deeply bipinnatifid, the lobes of the pinnae contiguous; fertile fronds either with fertile pinnae only or with the fertile pinnae at mid-frond, sterile pinnae above and below.