Seen at the Lady Bird Johnson Wildflower Center, near Austin, Texas — but found nearly worldwide — it’s a living fossil:
Equisetum (a genus containing 15 species) is the only living genus of the once-diverse family Equisetopsida. These now-odd plants first appeared in the late Devonian (some 100 million years after the first land plants made their appearance), and for more than 100 million years dominated the understory of Earth’s forests. Members of the family even grew as large trees, some 30 meters tall.
But today, the horsetails play a more humble role, typically growing no more than 1.5 meters tall, but native to nearly the entire planet’s surface — essentially all but Antarctica, Australia, and New Zealand. Unlike most plants, they reproduce via spores (rather than by seeds), and so are closely related to ferns.