A primitive vascular plant with jointed, hollow stems and whorls of scale-like leaves, reproducing by spores produced in cone-like structures. Horsetails are living fossils, the sole survivors of an ancient group that dominated Carboniferous swamps.
Named for the resemblance of the branched, segmented stems to a horse's tail, from Old English. The scientific name Equisetum comes from Latin 'equus' (horse) and 'seta' (bristle), reflecting the same visual similarity.
Horsetails are nature's scrub brushes, containing so much silica in their stems that they were traditionally used to polish metal and clean pots! They're also botanical survivors, essentially unchanged for 300 million years, making them older than dinosaurs.
Complete word intelligence in one call. Free tier — 50 lookups/day.