I have had this fern for many years growing on my allotment and I have no idea where I got it and what it was. If you gave it to me, please email me and let me know! It has a relatively fast growing horizontal rhizome and the fronds are around 90 cms tall
I sent these pictures to Christopher Fraser-Jenkins and this is what he wrote
That’s another old Himalayan friend of mine, Dryopteris ramosa – an interesting and rare case of a West Himalayan endemic. As far as I could guess its nearest relative is the Japanese endemic D. shiroumensis. Nothing in the east Himalaya or China like it!
There is another descriptive image here
Whilst photographing it, it shed enormous amounts of spores which I will send to the Spore Exchange