Adiantum L.

False indusium covering and bearing the sorus, consisting of a sharply reflexed, flap formed by the lamina(Fig. 17). Rhachises and stipes black or dark brown Adiantum
Each ultimate frond-segment attached by a comparatively long stalk coming from the middle or almost the middle of the base, not dimidiate.
Each ultimate frond-segment attached by a very short stalk at the lower corner of the segment, dimidiate