Cinnamon Fern Through the Lens of Time

DAILY BULLDOG • July 25, 2026

In the Northeast, cinnamon fern is one of the easiest ferns to recognize when its cinnamon-colored spikes are still present. Remarkably, the cinnamon fern has changed very little over time, appearing in the fossil record in late-Cretaceous rocks, and its lineage has remained stable even longer. In 2014, researchers described a 180-million-year-old fossil rhizome of a close relative from a volcanic mudflow in Sweden, where mineralization was so rapid that nuclei and even chromosomes were preserved. These matched those of the modern cinnamon fern almost exactly in size and number. Why have cinnamon ferns changed so little from the times that the last dinosaurs were walking among them? Possibly because the wet, acidic, low-nutrient ground that suits cinnamon fern has existed continuously on the planet since the Mesozoic, and because traits like tough rhizomes and quick-germinating green spores work so well in those wetlands that there has been little pressure to change. ~ Naya Banerjee