Fern ID needed

I like this fern in my sister's yard and would acquire more for both of us if I knew what to look for. Photo is the underside of a fertile frond.

Dryopteris species

Resin

Any idea which one?

Nope! Try the key in Flora N America: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=110995

Resin