Adiantum hispidulum.
The Rough Maidenhair Fern is a terrestrial fern whose short rhizomes have runners and fine rootlets.
It is covered with pale or dark brown triangular scales that are attached at their base.
Frond stalks are up to 30 or 40 cm long and the lamina is up to 30 cm.
The rough stalks are black or very dark brown with scales and reddish hairs.
The lamina midribs have similar stiff hairs.
The lamina is forked a few times at the base and the end branches are once divided.
The lateral leaflets or pinnules, up to 13 mm long and 5 mm wide are on short stalks.
They have a straight lower margin and the upper margin has small lobes or teeth.
There are white hairs on the leaflets.
There is one vein along the lower straight leaflet edge with forked side veins running to the upper edge.
The sori are protected by a circular or kidney-shaped false indusium formed by a flap from the leaflet edge folding back.
The soral flap has stiff dark brown hairs on it.
Spores are brown.
There is a lot of variation between populations of this fern and the species is sometimes divided
into 4 subgroups based on the extremes of the variations.
J.F.
