Over 100 million years ago, the understory of late Mesozoic forests was dominated by a diverse group of plants of the class Equisetopsida. Today, only one genus from this group, Equisetum (also known as horsetail or scouring rush), exists — and it is a prime candidate for being the oldest extant genus of land plant. The authors of this study showed that the plant developed a successful set of tools for life in extreme environments and has maintained them for millions of years.