Horsetails are ancient plants belonging to the genus Equisetum, which have existed for over 300 million years. They are characterized by their jointed stems and whorled leaves, resembling green tubes. Horsetails thrive in wet, marshy areas and can grow up to three feet tall. They reproduce using spores rather than seeds, which are produced in cone-like structures at the tips of their stems. These plants are often considered a living fossil, as they are one of the few remaining members of a group that was once widespread during the Carboniferous period. Horsetails are also known for their high silica content, making them useful for various purposes, including traditional cleaning and polishing.