Wisconsin Seed-free Plants
The best manual to identify lycopods and ferns is Ferns of Northeastern and Central North America (2nd ed.) in the Peterson Field Guides
Families and genera (and thus species names) are changing quickly in the seed-free plants
Carboniferous forest from Illinois
This group arose in the Later Silurian about 420 million years ago and was dominant in the Carboniferous and used to be much more diverse.
club mosses, spike mosses, quillworts
Leaves microphylls: generally small, simple, one-veined leaves. Microphylls evolved by the process of enation and vascularization. An enation is a veinless, lateral protrubence on the stem. When the enation becomes vascularized it is termed a microphyll.
Sporangia: the spore producers on the sporophytes are located singly on the upper surfaces or in axils of the bracts of a cone or of green leaves
Lycopodiaceae - club mosses
15 genera and about 375 species
Lycopodium now split into several genera
cosmopolitan distribution, most diverse in tropics
Evergreen, stems elongate and dichotomously branching. Leaves often densely covering the stem.
Oily compounds in the cell walls ignite rapidly into a flash of light and were used by magicians and sorcerers in the Middle Ages. More recently they were used as a flash early in photography and in experimental photocopying machines. Many species over-collected for Christmas wreaths.
Diphasiastrum complanatum Ground cedar, crowfoot