Scientists have discovered a fern "love child" in the mountains of France and found that it is the result of a puzzling reunion, providing insight on plant reproduction, according to a new study.

About 60 million years ago, an oak fern and a fragile fern - two distantly-related groups of plants - went their separate ways, stopped exchanging genes and split into separate lineages. However, despite this evolutionary breakup the two plants managed to create offspring in the form of a delicate woodland fern, found on a forest floor in the French Pyrenees.

For most plants and animals, reuniting after such a long breakup is thought to be impossible due to genetic and other incompatibilities between species that develop over time. It is so unusual that researchers compare it to an elephant hybridizing with a manatee, or a human with a lemur.

Beside this latest case, there have only been a couple other documented instances in which species have rekindled their relationships after an extremely long separation. For example, scientists observed tree frog species that successfully produced offspring after going their separate ways for 34 million years, and sunfish who hybridized after nearly 40 million years.

Until now, those were the most extreme reunions ever recorded.

"For most plant and animal species, reproductive incompatibility takes only a few million years at the most," Carl Rothfels from the University of California, Berkeley, who led the study, said in a statement.

But after extracting plant DNA from the newly discovered woodland fern, researchers realized that they had another rare instant of interbreeding after millions of years of separation.

So how is this even possible? Well, the study team credits this phenomenon to the manner in which ferns reproduce. These plants need a recipe of just wind and water to spread their pollen for them. So even after a long time apart, ferns can rekindle their relationship.

The findings were published in the journal The American Naturalist.

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).