Like all the Polypodies the clusters of sporangia have no indusia.
The indusia are soon thrown off when the spore cases start to develop.
The indusia of the areoles next the midrib are also often bent at an angle, and the two portions plainly united.
The sori are quite naked, no indusia being present at any time.
Sporangia near or on the margin of the segments, the reflexed portions of which serve as indusia.
The two plants might be difficult to distinguish were it not for the difference in their indusia.
The reason for linking the species with the Polypodies is found in the rounded sori, which have no indusia.
In systematic botanies the indusia play an important part in determining genera.
The sori have indusia, but this is hidden by the margin of the pinnules, which are recurved.
With the disappearance of the indusia the sori tend to spread over the whole surface of the back of the frond.