Ferns are primitive plants that first appeared 350 million years ago during the Devonian period.
In the spring, fern's can be seen uncoiling from below ground to continue their cycle of life. They expand to form mature leaf-like fronds. Spores produced by the fronds fall to the ground and germinate much like a seed. A small, rarely seen, heart-shaped structure grows out of the spore. This structure can produce both eggs and sperm. In ferns, sperm swim in moisture that collects on the heart-shaped plant to reach the egg, so as a group ferns are tied to moist environments. Once the egg is fertilized a new frond grows and the life cycle continues. As winter approaches many ferns die back and overwinter under the soil, but some such as the Christmas Fern overwinter above the soil.
Unlike flowering plants that reproduce by making seeds, ferns reproduce by producing microscopic cells called spores. These form in specialized structures that are grouped together to form sori. Sori can be located on the underside of green fertile fronds or on structures lacking leafy tissue. The shape and arrangement of sori helps distinguish the different classes of ferns. Often sori are covered by a layer of cells known as the indusium. As the spores ripen the indusium dries and shrivels exposing the sporangia. When fully ripe the sporangia split open and the spores are released.
The leaf-like portion of the frond is also used to help distinguish different fern species. The frond can appear as a single leafy structure or be subdivided into simple pinnae. Pinnae can be further divided into pinnules and the pinnules can be further divided into teeth or lobes.
• Maidenhair Fern, Adiantum pedatum
• Pinnatifid Spleenwort, Asplenium pinnatifidum
• Ebony Spleenwort, Asplenium platyneuron
• Maidenhair Spleenwort, Asplenium trichomanes
• Northern Lady Fern, Athyrium felix-femina
• Glade-fern, Athyrium pycnocarpon
• Silvery Spleenwort, Silvery Glade-fern, Athyrium thelypteroides
• Walking Fern, Asplenium rhizophyllum
• Bulblet Bladder Fern, Cystopteris bulbifera
• Fragile Fern, Cystopteris fragilis
• Lowland Fragile Fern, Cystopteris protrusa
• Intermediate Shield Fern, Dryopteris intermedia
• Marginal Shield Fern, Dryopteris marginalis
• Spinulose Shield Fern, Dryopteris spinulosa
• Sensitive Fern, Onoclea sensibilis
• Christmas Fern, Polystichum acrostichoides
• Virginia Chain Fern, Woodwardia virginica
• Hay-scented Fern, Dennstaedtia punctilobula
• Bracken Fern, Pteridium aquilinum
• Common Grape-fern, Botrychium dissectum
• Blunt-lobed Grape-fern, Botrychium oneidense
• Rattlesnake Fern, Botrychium virginianum
• Cinnamon Fern, Osmunda cinnamomea
• Interrupted Fern, Osmunda claytoniana
• Rock-cap Polypody, Polypodium virginianum
• Broad Beech Fern, Thelypteris hexagonopteral
• New York Fern, Thelypteris noveboracensis
• Marsh Fern, Thelypteris palustris
• Long Beech Fern, Thelypteris phegoteris
*This list is compiled from "The Vascular Flora of the Galcieated Allegheny Plateau Region of Ohio," by Barbara K. Andreas, a 1989 publication of the Ohio Biological Survey.