AP BIOLOGY

Detailed explanation-1: -Horsetail is derived from huge, tree-like plants that thrived 400 million years ago during the Paleozoic era. A close relative of the fern, horsetail is a nonflowering weed found throughout parts of Europe, Asia, the Middle East, and North America.

Detailed explanation-2: -Horsetails can be considered living fossils. This group of plants is what is left of a group of plants that were as thick as forests and had relatives as big as trees that flourished during the Devonian period approximately 350 million years ago.

Detailed explanation-3: -Horsetails, like their close relatives the ferns, are evolutionarily ancient plants and don’t produce seeds to protect and nourish their offspring. The sporophyte, or diploid, phase of the Equisetum life cycle is the dominant one and is represented by the herbaceous stems described above.

Detailed explanation-4: -horsetail, (genus Equisetum), also called scouring rush, fifteen species of rushlike conspicuously jointed perennial herbs, the only living genus of plants in the order Equisetales and the class Equisetopsida.