Phlegmariurus pringlei
Phlegmariurus pringlei was a common epiphyte in many of the sites that we visited in Oaxaca. Adventitious roots were often observed at the distal parts of its stem, apparently resulting in vegetative propagation whenever the plants touched a suitable substrate. The...
This looks like Thelypteris dentata (Forssk.) E.P. St. John
Notice the hyaline acicular hairs, and reniform indusia.
Thanks. I did not notice the hairs.
I agree, Thelypteris dentata, also often known as Christella dentata. Plants of the Neotropics are all introduced, beginning ca 1900, in Brazil. Now, this species is possibly the most often collected fern in the Neotropics, from SE United States, West Indies, and Mexico to Bolivia, Brazil, and Argentina. The species is native and widespread in the Paleotropics, but naturalized and common in Hawaii and some other Pacific Islands. It is a very common greenhouse weed, as well as weedy in both its native and naturalized habitat.
Great. Thanks to both you and Michael for the det. The post has been updated.