Dryopteris ×neowherryi is a hybrid between D. goldiana and D. marginalis.
Polystichum acrostichoides

Dryopteris ×neowherryi is a hybrid between D. goldiana and D. marginalis.
When I traveled to California, the last fern that I was expecting to find outdoors was Regnellidium diphyllum, a narrow endemic species from S Brazil, N Argentina, and Uruguay. But there it was, vigorously growing in a garden pond. Almost everything about this fern...
Very nice – the medial position of the sori is killer for this hybrid.
Is this the plant from Duffy’s Swamp?
No, this is the plant that Art Gilman showed us.
Beautiful hybrid! Very rare in nature, I presume. By the way, do you know if David still has copies of “Henry Potter’s field guide to the hybrid ferns of NE”? I would like to buy one…
They are available from the Tryon Pteridophyte Library http://www.uvm.edu/~plantbio/pringle/Libraries.html
Thanks for the link! I will buy it tonight. That website is amazing, btw… I loved that photo of the Tryons in their early days. I also enjoyed reading about Cyrus Pringle (what a beard!) and the profiles of important collections at VT.