• Most of the seedless vascular plants that flourished for about 60 million years in the past are extinct.
• Their present-day descendants (whisk ferns, lycophytes, horsetails, and ferns) differ from bryophytes with respect to the sporophytes.
• The sporophytes develop independently of the gametophytes, have well-developed vascular tissues, and are the larger, longer lived phase of the life cycle.
• All of them have developed vascular tissue which allows for the formation of true leaves, stems, and roots.
• Xylem conducts water and minerals up from the roots, while phoem carries organic molecules down from the leaves.
• The development of vascular tissue also solved the problem of support against gravity.
• Although the sporophytes of seedless vascular plants can live on land, their gametophytes cannot because they lack vascular tissues and the male gametes must have water to reach the eggs.
• Whisk Ferns (Psilophyta) look like whisk brooms and are not true ferns. The sporophytes have no roots or leaves, but rather consist of a system of scalelike branches. The stem houses the xylem and phloem as well as surface cells capable of photosynthesis. Underneath the ground surface short, branching rhizomes serve an absorptive function.
• Lycophytes (Lycophyta) were once tree-sized but now are represented by small club mosses on the forest floor. The sporophyte has true roots, stems, and small leaves containing the vascular tissue. Strobili bear spores that germinate to form small, free-living gametophytes. This group is still closely tied to an aquatic environment because the sperm must swim to the eggs.
• Horsetails (Sphenophyta) had ancestors which were treelike; only the moderately sized Equisetum has survived. The sporophytes possess underground stems called rhizomes. The scalelike leaves are arranged in whorls around the hollow, photosynthetic stem. Spores are produced inside cone-shaped clusters of leaves at the shoot tip.
• Ferns (Pterophyta) bear underground stems (rhizomes) and aerial leaves (fronds). Sori are clusters of sporangia that release spores that develop into small heart-shaped gametophytes.

Click on the Internet links below for more information.

The American Fern Society. Includes an introduction to American ferns, basic fern biology, and information about how to grow ferns. Click on Fern Basics to start.

Ferns of the Canberra Region. Many photos of ferns from Austalia.

Pteridophytes. An ecological review of the importance of ferns, what is known, and what is not known.

Ferns. A review of the life cycle courtesy of the Kimbal, General Biology text.

The Ferns. Everything about the ferns is discussed here in this University of the West Indies page.

Milwaukee Public Museum. Their introduction to the ferns with excellent photographs. Note specifically the sporophyte and gametophyte distinctions.

Non-Flowering Plant Family Access Page. This University of Hawaii page provides links to information about the Psilotaceae, Lycopodiaceae, Selaginellaceae, Equisetaceae and several families of ferns. There are many excellent photos.

Introduction to the Lycophyta. Introduction to the club mosses and scale trees provided by the University of California Museum of Paleontology. Be sure to click on the four icons at the bottom.