Hartford fern is a North American native. The name “Thoreau’s climbing fern” originates from
an 1853 sighting by Henry David Thoreau, later verified, in an impressive show of
scholarly thoroughness, by Ray Angelo. Hartford ferns, once gathered
for Christmas decorations, have the interesting distinction of being the first endangered
species—the first plants protected by law against
picking in the United States.
Identification: This fern manages to combine the
properties of a vine, a fern, and a palm in a single species. (And maybe willow as well, since the
genus Lygodium derives from a Greek word meaning “willow-like.”) Unlike most ferns, it clambers over
other plants with a long, thin woody stem (rachis), which may reach 15' (4.6 m) in length. Its deeply divided leaves are fernlike, but also
palmate, with 3-7 spreading blunt-tipped fingerlike lobes.
ID is uncertain 
