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Lower Vascular Plants

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This page treats the three lower vascular plant divisions; the Psilotophyta, Lycopodiopsida, and Equisetopyhta.

Bio216: Vascular Plants. Dan Skean. An introduction to the classes of the lower vascular plants with information about morphology and links to photographs of four representative species.

The subphylum Psilotophyta (Psilophyta or Psilopsida) represents the most primitive vascular plants. These plants arose in the Silurian and Devonian and are characterized by the presence of tracheids, but they lack true roots or leaves. The group is probably completely extinct, although two genera (Psilotum and Tmesipteris, neither found in North America) are sometimes placed as members of this primitive group.

Division Psilophyta. Francis Cardillo. This site has information on the genus Psilotum with a photograph and discussion of its life cycle.

Division Lycophyta. Francis Cardillo. An outstanding introduction to the Class Lycophyta and the three living orders comprising it; Lycopodiales (Clubmosses), Selaginellales (Spike Mosses), and Isoetales (Quillworts). You can find extensive information on each here with photographs of representative species.

Lycophyta: Life History and Ecology. Museum of Paleontology, University of California at Berkeley. An introduction to the Lycophyta with information on their biology, life histories, systematics, and fossil record.

Classification of Plants - Division Sphenophyta. Francis Cardillo. This site has an excellent introduction to the horsetails with information about biology and life cycles with specific details and photographs on three species.

Sphenophyta. Museum of Paleontology, University of California at Berkeley. This site has an extensive and excellent introduction to the horsetails. It is strongest in morphology, biology, systematics, and the fossil history of the group.

Equisetaceae. University of Hawaii, Gerald Carr. This site contains photographs and information on the horsetails (Equisetum).

Brousseau Collection of California Wildflowers. Berkeley Digital Library Project. Photographs and information on the California species of horsetails (Equisetum) may be found in this database of photographs of California Vascular Plants.

Albion College Vascular Plant Image Gallery. Dan Skean. Photographs of two species of Equisetum.

Vascular Plant Image Gallery. Texas A&M University. Photographs of some species of Equisetum.

Wisconsin Plants. Photographs of species of Equisetum.