horsetail definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
- a horse's tail
- any of the only surviving genus (Equisetum) of a division (Equisetophyta) of plants having hollow, jointed stems, with scalelike leaves at the joints and spores borne in terminal cones; scouring rush
horsetail definition by American Heritage Dictionary
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Any of various nonflowering plants of the genus Equisetum, having a jointed hollow stem and narrow, sometimes much reduced leaves. Also called equisetum.
horsetail - Science Definition
A member of a genus, Equisetum, of seedless vascular plants having a jointed hollow stem and narrow, sometimes much reduced leaves. Plants extremely similar to modern horsetails are known from fossils 300 million years old. The horsetails are the last surviving members of the phylum Sphenophyta, which dominated the forests of the Devonian and Carboniferous periods.