Ferns

Conjure an image of a fern in your mind. What is likely to fill the space is a large, lacy frond, illuminated by dappled light in a damp forest understory. You may also have been transported back in time millions of years ago, to a prehistoric landscape shrouded with ferns and dinosaurs. We often think of ferns as old, shade-loving, understory plants in temperate forests. While the lineage dates back 400 million years, and while many ferns do occupy such a niche, this evolutionary and ecological pigeonhole couldn't be further from the truth. Ferns are not hanging on by a thread in refugial environments — they are an evolutionary success story, persisting and diversifying into one of the most species-rich and biologically diverse groups of vascular plants, just behind the angiosperms. In this primer, I will expound on their evolutionary history, species richness, and modern ecological diversity, highlighting what they are and how they came to be.