Pioneer Valley Fern Society

Winter Ferns 2024-2025

Maidenhair Spleenwort in ice

With the snow lately it is getting harder to see most of our ferns this month. But in certain spots on rock faces, where there is enough water to form ice waterfalls, we can find beautiful Maidenhair Spleenwort (Asplenium trichomanes) encased in the ice. This photo was from one of those spots at Mt Toby, along the Tower Rd. By the general size and shape of the fronds, you can probably tell it is one of the spleenworts, either Maidenhair Spleenwort or Ebony Spleenwort. The easiest way to tell the difference between these two when the normal shape of the fern is obscured by the ice, is to look at the pinnae or leaflets. Maidenhair Spleenwort pinnae are like a rectangle with rounded corners. Ebony Spleenwort pinnae are elongated, and are similar in shape to Christmas Fern pinnae, with a little "ear" or auricle projection on the upper side of the base of each pinna. The sori are usually visible through the winter on both Spleenworts. The Maidenhair Spleenwort usually has only 3 pairs of sori on the back of the fertile pinnae. The Ebony Spleenwort, with its longer pinnae,have 7 or 8 pairs of sori on the fertile pinnae. They are usually not found growing in the same area, so it is hard to do a side by side comparison.

Posted: to PV Fern News on Mon, Feb 3, 2025
Updated: Mon, Feb 3, 2025