Etymology Greek: a, not + splen, the spleen. A totally confusing reference to the use of spleenwort to cure spleen and liver problems. The name originated with Pliny and Discorides.

Description Rhizome: erect, scales clathrate.
Frond: evergreen, monomorphic or nearly so.
vascular bundles: 2 C-shaped, back to back, uniting to 1 upwards to an X-shape.
Blade: simple to 2-pinnate, commonly with tiny glandular hairs and a few linear scales.
veins free.
Sori: linear, indusium: thin, flap-like, covering sorus during maturation, on one side of the sorus.

Distinctive Characteristics The stained-glass effect on rhizome scales is unique. The linear sorus along veins is characteristic.