Climbing Fern

 

Last Saturday, Shauna and I participated in the Beaver Christmas Bird Count. Our area of the count covers a very remote area of Jackson County, Ohio, and it was quite birdy, at least in regard to species diversity. Overall numbers were not great. Highlights included five Hermit Thrushes and two Eastern Phoebes. In all, we found 43 species. And reconfirmed the existence of this population of Climbing Fern (Lygodium palmatum).

ASIDE: Hermit Thrushes are undoubtedly far more common in wintertime southern Ohio than is generally imagined. One key to finding them is getting an eye for suitable habitat, which is hardly rocket science. They favor early successional habitats with plenty of fruiting sumac (genus Typha) and most commonly from my experience, Staghorn Sumac (Rhus typhina). The copious and long-persistent sumac fruit is a staple of their wintertime diet. Once in a while, one will hear the easily recognized low chuck call note of a thrush and find it that way, but mostly, the birds remain silent in dense cover and are easily overlooked. But judicious playing of the thrush's call note - not the song - will usually elicit a response, quickly. Had I not done that, we probably wouldn't have found any on this excursion. Had we had more time to just work Hermit Thrushes, we may well have doubled that number.

Back to the fern. The above photo shows Climbing Fern's scrambling growth habit. It isn't hard to spot a colony, but colonies tend to be fairly rare and local and widely scattered. At one time, it was on the Ohio Department of Natural Resources' official list of rare plants but was rightly removed long ago as it isn't rare enough to merit listing.

Map courtesy of the Flora North America

This is the only member of the largely tropical fern family Lygodiaceae that occurs entirely within the Unites States, and by far the most northerly species. Two others, Asian species and both in the genus Lygodium, have been introduced. One of them, Japanese Climbing Fern (L. japonicum) is widely established across the southeastern states but has not yet managed to make it as far north as Ohio. The other is Climbing Maidenhair (L. microphyllum) which thus far is confined to Florida but seems to be rapidly spreading.

Aptly named, Climbing Fern is adept at scrambling up supporting vegetation, and can climb to several feet in height via its spaghetti-like orangish stems. The green conspicuous fronds are the sterile leaves that are long-persistent. The fertile spore-bearing leaves are short-lived and quite different in appearance. Remnants of these can be seen at the bottom one-third of the plant in the image above. They are the lacy brown extensions from the stems.

The fern's specific epithet, "palmatum" essentially means "hand-like" and the fronds certainly suggest hands. In the fern world (Pteridophytes), which encompasses about 80 species in Ohio, Climbing Fern is among our most distinctive species.

I first saw this Climbing Fern colony over 20 years ago, and it's always rewarding to revisit it each year. The general area in which it occurs has a large silica mine that is still operational and has laid waste to lots of interesting and valuable habitats since it started. Hopefully this fern colony and its vicinity will be spared, especially as there are several other rare plant species nearby, including some that are truly endangered.