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.