Name: Evan Pioneer Valley south, MA, USA (Zone 6a)
Thanks Myriam. Wish I could find some info. on this fern. If not for your photos showing spores I'd never have guessed. Since it's an epiphyte and the stems are above ground I wonder why they're defined as rhizomes.
Yes, the term 'rhizomes' in this case is not really appropriate but that is how a botanist who identified it, called them at the UBC Botanicalgardens.
Probably they are not evident to grow out of their natural rainforest habitat!