Gary Fewless

Key to the Ferns

The key includes all native ferns known to occur in Wisconsin. Each page offers two alternatives. Select the choice which best suits the specimen at hand, click on the numeral to the right and you will be presented with another page with another set of choices. This process continues until you reach an answer. Photos used within the key are examples to illustrate the terms and may not be a perfect match for your specimen, especially early in the key where any given step may lie along the path to many subsequent species.

1. Fertile fronds conspicuously different from sterile fronds in shape and/or color, or fertile portion of a frond on a separate branch.
1. Only one type of frond produced, with sori borne on the undersurface of pinnae which are otherwise the same as if sterile.

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