I just returned from a week of camping in the Great Smoky Mountains of Tennessee and North Carolina, where we saw a surprising number of ferns. Some of the most beautiful ones were several species in the genus Asplenium. There are around 700 species in this genus worldwide, but fewer than 30 in North America, and fewer still that are easily found. We were lucky enough to see four (count 'em, four!) during the course of this trip; I had only seen one Asplenium ever in North America before, so this was quite a take. All four are pictured above and their names are, in alphabetical order:
Asplenium montanum (Mountain Spleenwort), Asplenium platyneuron (Ebony Spleenwort), Asplenium rhizophyllum (Walking Fern), and Asplenium trichomanes (Maidenhair Spleenwort).
It was especially fun to see this particular group of species, because three of them are veritable celebrities among Aspleniums: A. montanum, A. platyneuron, and A. rhizophyllum make up the three corners of the so-called "Asplenium triangle," a group of species that involve several putative parents (those three species) and many combinations of those three that have formed hybrids, some of which have become good, fertile species in their own right. Cool to see them!