The American Hart's-Tongue Fern is an interesting plant.

"It’s one of the rarest ferns in the United States so not too many people are familiar with it or have seen it or will ever see it," said Mike Serviss, ESF graduate student in conservation biology.

And where it likes to grow doesn’t make it easily accessible, like Clark Reservation near Jamesville, New York.

"One of the unique things about it is it grows in an area that’s a very specialized habitat, very rich in limestone on very steep slopes," Serviss said.

Or, even more inaccessible, like in this sinkhole in Tennessee.

"We actually had to repel into that site it’s about 70 feet or so down," Serviss said. "So yes they have these really unique habitats that kind of differ throughout their range as well."

However, Mike Serviss and other researchers are working to augment current populations by jump-starting them in the lab and finding just the right time to plant them to maximize the likelihood of survival.

"What we’re looking to do is get the number back by introducing them to spots where maybe they once were, but aren’t doing so well and augmenting populations that are already there and boost the numbers so they have a lower chance for extinction in the future," Serviss said.

American Heart’s-Tongue Fern is also found in Alabama and Michigan but their total population is very low.