Well, those sori rule out Todea, Cyathea, and Dicksonia, none of which would have the sori on the leaf margins protected by a false indusium composed of the reflexed leaf margin. From here, this looks like bracken, Pteridium aquilinum.

Patrick Alexander

I think the sori of this fern do not look like Todea, not like Cyathea and not like Dicksonia. The rhizome looks also not like Pteridium, Pteridium has a creeping rhizome and stipes are always green and they stand distant from each other at the rhizome not clustered. Sori looks like a species from Pteris for me similar to the sori at this photo.
{{gwi:613027}}
regards
Athyriana
www.farngarten.de

Thank you so much for your input paalexan and Athyriana. If I carry on with a process of elimination I may eventually find out what fern it is. I am now sure that the sori rules the first identifications out. It also appears as if it is definitely not a Pteridium aquilinum because of the nature of the rhizome. My question now is: Is there not a Pteridium with a rhizome like the one in my picture? (Not a creeping rhizome)
Thanx again

Pteridium rhizomes are always creeping and fronds never standing in a cluster. The rhizomes creep subterranean. You can't see the rhizome. It sometimes creeps up to 1 m under the surface. The genus Pteridium has only one species "aqilinum".
The fern at your photo could be a Pteris quadriaurita, that grows up to 1,2 m in high and I saw plants with such brown stipes in a Botanical Garden.
regards
Athyriana

Yeah, I think you're right, Athyriana. I hadn't stopped to think about the rhizomes...

Patrick Alexander

Athyriana, you were very close. It is actually a Pteris tremula from Nieu Zealand.
Thank you for your inputs.