2022-2023 Winter Ferns

#5 Maidenhair Spleenwort

Maidenhair Spleenwort (Asplenium trichomanes) is one of the prettiest of our local native ferns. It is a common rock-loving fern, usually found on mossy rock faces, rooted in little nooks and crannies or under overhanging ledges. It is hard to get a photo of it with snow, since it seems to be situated in places where the snow melts quickly from the winter sun. It is considered an evergreen fern since the fronds remain green through the winter.

Maidenhair Spleenwort is distinctive and easy to recognize. It has shiny purplish-brown stems (rachis and stipe), and small rounded leaflets (pinnae). It is found throughout the Northeastern states, most of the United States including Alaska, as well as Canada, Europe, Africa, Asia and the Indo-Pacific (Cobb/Farnsworth/Lowe, Ferns of Northeastern & Central North America). It was named by Linnaeus from European specimens in 1753, but "trichomanes" had been used for this fern well before Linnaeus (Tyron & Moran, The Ferns and Allied Plants of New England,1997). In our area we see it often on various parts of Mt.Toby, as well as at Chard Pond, and Bartons Cove. This photo is from Chard Pond.

In reading up on the Maidenhair Spleenwort in several books, I found something I did not know before! According to Tyron & Moran, Chadde (Northeast Ferns), and Cobb/Farnsworth/Lowe, there are two subspecies found in our area. The differences are both chromosomal and by habitat preferences. Without trying to explain it in any detail (which I can't do), the diploid race, Asplenium trichomanes subspecies trichomanes, is found growing on acidic to neutral rock such as sandstone, basalt and gneiss, while the tetraploid race, Asplenium trichomanes subspecies quadrivalens D.E. Meyer is usually found on calcareous rocks such as limestone and dolomite. Therefore, it is most likely that we are looking at Asplenium trichomanes subspecies trichomanes around here, in case anyone asks!