Stems are hollow except at the nodes, giving them a jointed appearance. Most ferns have large leaves called fronds which are usually made up of smaller leaflets. They reproduce by means of spores. Next to flowering plants, ferns are the most diverse group of plants in the division Tracheophyta. Gymnosperms reproduce by means of naked, or uncovered, seeds.
Many gymnosperms are evergreens with a wide variety of leaf structures.
Conifers, cycads, ginkgoes, and gnetaleans are in this class. Cycads grow fern or palmlike leaves. Their seeds are borne in large cones. Many species have unbranched, erect stems, while others have partially underground stems called tubers. Some cycads are trees.