Learn your Settle Ferns 3: Hard Shield Fern and Soft Shield Fern = Polystichum aculeatum and Polystichum setiferum

These two Shield ferns are both twice pinnate. (i.e. they have a frond divided into pinnae which are divided into pinnules.

The teeth on the pinnules end in points.

In the Shield Ferns,  on each pinnule, the pinnule tooth nearest the main stem points in the direction of the stem rather than the direction of the pinnule - So it sticks out like a thumb. 

In Soft Shield Fern 
the pinnules are actually on little stalks 
and the base of the  pinnule is obtuse, or at least 90 degrees.

In Hard Shield Fern the base of the pinnule is acute and the lamina goes right down to the stem of the pinna, the pinnule is not stalked.

Soft Shield Fern, Castleberg Rock, Settle

Hard Shield Fern, Catrigg Foss

Hard Shield Fern at Catrigg Foss

Soft Shield Fern Castleberg rock

Soft Shield Fern Langcliffe

Lady Fern and Male Fern are two common ferns in our area which are also both twice pinnate - but the do not have points on the pinnules - they are blunt. And they don't have the "thumbs"

The vast majority of Shield Ferns that I find around here are the Hard Shield Fern. It grows on Limestone.

I used to say "Soft Shield Fern does not grow around Settle". but now I have found it in two places -plus the Ley of the Land Garden Centre.