The Carlisle Mosquito Online

Friday, March 8, 2002


Marginal Woodfern

Name: Marginal Woodfern or Dryopteris marginalis, a.k.a. Leatherleaf Woodfern.

When and where seen: Found by Tom Brownrigg in several wooded locations in the Great Brook Farm State Park last weekend and throughout the winter.

Distinguishing characteristics: This fern has several characteristics that make it quite easy to identify. First, it is one of our evergreen ferns standing out nicely in the winter against a background of dead leaves. Secondly, the fronds are twice-cut, meaning that the leaflets are divided into sub-leaflets. Other evergreen ferns are once-cut like the Common Polypody and the Christmas Fern, or thrice-cut and lacy like the Spinulose Woodfern. Thirdly, the fruit-dots are positioned at the edges of the leaflets, hence the name Marginal Woodfern. The tips of the sub-leaflets are rounded. The rootstock is usually exposed and shows the remains of older withered stalks. Also, the fronds are rather tough and leathery ­ I guess you could say the fern has a thick hide and doesn't mind being called "marginal". The Sensitive Fern (Onoclea sensibilis) might not be able to handle such a name.

Habitat: The clumps in the State Park tend to be in the more upland locations, and are growing along with the Common Polypody in shallow layers of soil on top of rocks.

Reference: Boughton Cobb, A Field Guide to Ferns, published by Houghton Mifflin.

Correction: The Long-tailed Weasel in last week's column was inadvertently reported as weighing up to 9 pounds instead of 9 ounces. That would be a giant sumo weasel not actually known to exist. Apologies to all and regrets to any who were frightened.

Submissions for the Biodiversity Corner are encouraged from everyone. You can write the column or tell me what you saw and I will write it. The only requirements are that the species exists in the wild and was seen in Carlisle. It could have fur, fins, feelers, fronds, or feathers. This request brought to you by the letter 'f'. Send a note to Kay Fairweather at 392 School St, Carlisle MA 01741 or to

2002 The Carlisle Mosquito