This item though, threw me for a loop:
I had no idea what it was, so I brought in inside, all soggy and crumbly, and commenced my search for an answer. (For reference, it is over a foot long, maybe 15 inches). Answers come from some unexpected places. I showed it to our handyman and he knew right away what it is: part of a fern, from the root end. Armed with this information, I grabbed my Fern Guide (Edgar T. Wherry) and started to flip pages. Sure enough, it is the rootstock of a fern (or, perhaps, the rhizome, according to Fern Finder by Anne & Barbara Hallowell).
According to Wherry, the wood ferns (Dryopteris spp.) have a "stout, scaly rootstock, holding old stipe-bases." This seems to fit what we found.
On my next trip out towards Pickerel Pass I will have to keep my eyes open for ferns and see if I can find any attached to similar rootstocks and thus obtain a definite ID.