This section is from the book "The Gardener's Monthly And Horticulturist V22", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
The Wissahickon is the name of a creek which coming from the north for some distance, empties into the Schuylkill river, Philadelphia. For several miles before reaching the Schuylkill, the Wissahickon runs its course between rugged and high hills. These hills and the occasional stretches of low lands furnished materials for study to many of Philadelphia's older botanists, and to-day it is the home of many a rare plant which botanists delight to find.
The beautiful and very interesting Walking Fern, Camptosorus rhyzophyllus grows there, as also does the rarer Asplenium pinnatifidum. The older botanists and collectors, if asked for the locality of the Walking Fern, would name but one or two places where it could be.found. It may have been with them as with many now, they feared to tell of localities where few existed lest their favorites should become exterminated.
The writer of this, within a couple of years, has found no less than five places along the Wissahickon where this fern exists in tolerable abundance.
The A. pinnatifidum however, is not nearly so abundant. The location of the banks of the Schuylkill where Nuttall found it, still retains the plants, and it is a pleasure to add, in some abundance.
It was lately my fortune to find it also along the Wissahickon, but the find consisted of but a single plant. As Dr. Gray states it is found there, it would be interesting if it could be known whether this single plant represents the old location, or is in a new one. For many years the Schuylkill was thought to be the only locality for this fern: but it is now found in other States besides Pennsylvania, though still considered rare.