Pteridophyta is a division of plants within the classification system that are all vascular in nature and reproduce by the means of spores. The most common examples are ferns, horsetails, and club mosses.

Pteridophytes achieved prominence in the carboniferous period, along with the dinosaurs. At that time, many giant forms of pteridophytes superficially similar to extant species existed. The largest were some 60 ft (20 m) tall, whereas the largest living examples alive today are the giant horsetails Equisetum giganteum which grow up to 15 ft (5 m). The pteridophytes are responsible for many of the coal and oil deposits around the world, and as living organisms, they are popular as decorative plants.

Extant pteridophytes are widely distributed around the world, although their greatest range of diversity can be found in the tropics. They are mostly vascular and terrestrial, with no secondary thickening. They show alternation of generation with the gametophyte form being dominant. The spores are usually produced on the underside of laves or cones, and there is still a great reliance on water for the fertilization process when it occurs.