Pioneer Valley Fern Society

2022-2023 Winter Ferns

#4 Climbing Fern

Most all of you are familiar with our most common evergreen or semi-evergreen ferns, which remain green through the winter. These include the Christmas Fern (#1 this year in this Winter series), Evergreen Wood Fern, and Marginal Wood Fern. If you want to brush up on Evergreen Wood Fern (Dryopteris intermedia) and Marginal Wood Fern (Dyropteris marginalis) check out the news articles from February 5th & 12th, 2022.

Much less common but present in our area is the Climbing Fern (Lygodium palmatum), which remains green through the winter despite its delicate appearance. Although not common, it can be locally abundant when it is growing under the right conditions, wet and sunny. Growing in the wild, it will look like a tangle of vines, as it climbs up nearby taller vegetation. In the winter, when the other vegetation dies back or loses their leaves, it is more visible in its true form.

This attractive fern has the distinction of being the first plant protected by law (1896 in Hartford CT). Another common name for this fern is Hartford Fern, because of that distinction. It is the only climbing fern in our region, and the only native one in North America. Most of this genus (Lygodium) grow in tropical areas. The entire frond is the viney rachis with all the palmate-shaped leaflets or pinnae. One plant can be up to 15 ft long. At the tips of the frond are the lovely fertile leaflets, which are much smaller than the sterile ones beneath them. Both are visible now in the winter.

If you see this fern you should report the location to the MA Natural Heritage & Endangered Species Program. It is considered uncommon in MA, CT & RI, and extremely rare in NH.