With the canopy fully closed shade is deep in the forests along the Great Allegheny Passage. Plants growing in the deep shade are specially adapted to the lower level of light, and they dominant the carpet on the forest floor. One group of plants that are of interest at this time of the year are the ferns.
Species with names like Christmas, evergreen wood, lady, polypody, hay-scented, New York, bracken, royal, cinnamon, interrupted and and maidenhair are among the nearly 100 species that can be found in Pennsylvania and western Maryland. Many of these flourish alongside the Passage.
Like the spring wildflowers, soils derived from different types of foundation geology, and having higher or lower moisture levels, harbor different species.
In dry acidic soils of oak forests the ground layer is dominated by New York and hay-scented fern. One, of many, example of these fern colonies is on the Pinkerton Horn around Mile 53, in Somerset County.
Moist limestone ledges are less common, but where they are found the delicate maidenhair fern decorates the wet ledges. Finnegan's Ledges at Mile 65 in Ohiopyle has some beautiful sprays of this species.
A summer adventure can be mounted with a slow ride and a good fern field guide. Taking the time to stop, find ferns growing along the Passage, and using the guide to identify your treasure can easily occupy a long summer day.