Today John and George, peparing a presentation at the Palm City Public Library (probably July 29 2016) explored a pretty St. Johnswort marsh adjacent to the library, with flowering St. Johnsworts, Tall Pinebarren Milkworts, Eupatoriums, and Rosegentians. We marveled at something we deemed marvelous long ago: that the leaves of Virginia Chain Fern line up along the snakey rhizomes often all facing the same direction like solar panels. Sometimes an entire meadow can have the VA Chain Ferns all in conformity. How much of this alignment is a slow growth response, and how much is a short-term adjustment will be interesting to measure.
However, back in 1899 a remarkable individual beat us to it fittingly, in Virginia…at the Great Dismal Swamp. I don’t normally provide a bio for every biiologist with a discovery before 2016, but William Palmer (1856-1921) was so exceptional, a few words might be interesting. Recording that Virginia Chain Fern orients to the sun was not his oddest feat. Contenders for that included stuffing the last passenger pigeon on earth (he did not kill it), making models of fish and squid still displayed at the Smithsonian Institution (where he worked), discovering an extinct seaturtle, casting a mold of a Mexican meteorite, preserving a whale skeleton, researching the Florida Burrowing Owl, and boiling eggs in a volcano. Palmer specialized in birds and ferns, which brings us back to Virginia.
Virginia Chain Fern has a huge north-south range, from here to northern Canada, mostly in the Atlantic Coastal Plain and into the Midwest. And that footprint a mere remnant. In 2001 botanists K. Pigg and G. Rothwell found our fern fossilized about 14 million years ago in Washington State, showing how the modern distribution of a plant may be misleading about its history. Who knows, it may have extended even into Asia.
You’ll never have trouble recognizing Virginia Chain Fern. Hold it up to the light, look at the bottom of the leaf, and see looping chains made by the veins.
The spore-making regions, called sori, develop bounded by the loops of the chain. According to some reports, the plants tend to enter their spore-making phase in response to disturbance.
Two reported spore-inducing stimuli are fire (no surprise) passing over the rhizome safe in the mud, and well, you guessed it of course, beavers. (What!?) That needs a little more research. But then again, the ferns do inhabit wet mud, and beavers make mud wet.