But ferns are an important exception. Ferns have multiple reproductive strategies. Most species combine spore development and photosynthesis on a single leaf type — a strategy called monomorphism.

But since the 1970s, geologists have also noted the existence of another layer, just above the iridium-rich one, that contains “lots and lots and lots of fossil fern spores” and not much else, says ...

Growing ferns is ideal if you have shadier spots in your backyard. The plants add beautiful form and texture to borders and containers, or trickier spots like under trees or darker corners.

In fact, we love them so much, we’ve filled our new Evolution Garden with them. But how much do you know about one of the earliest plants to evolve on our planet? Ferns have been growing on Earth for ...