Translations:Adventist Youth Honors Answer Book/Nature/Ferns/32/en

Horsetails, like club mosses and ferns bear spores rather than seeds. Horetails are in the order Equisetales which consists of a single family called Equisetaceae. There are 15 species in this order.

Equisetum arvense (Field Horsetail)

Equisetum arvense is a rather bushy perennial with a rhizomatous stem formation native to the northern hemisphere. These horsetails may have sterile or fertile stems. Sterile stems start to grow after the fertile stems have wilted. The sterile stems tend to be much taller and bushier, with the jointed segments being around one inch long with a diameter of about 1/20th of an inch. These segments contain one set of whorled, slender, erect branches each. Some stems can have as many as 20 segments and be as tall as 2-24 inches. The fertile stems tend to be half as tall as the sterile stems and also tend to be more succulent.