Polypodium glycyrrhiza
Common name: Licorice fern
Polypodium glycyrrhiza is native to the Pacific Coast up to Alaska. It commonly grows epiphytically on tree branches or trunks, especially those of Acer macrophyllum (big-leaf maple) or as a lithophyte [on rocks]. The rhizomes contain ostadin, a compound 3000 times sweeter than sucrose. Coastal native peoples used the rhizomes as a sweetener and for treating throat ailments. The name Polypodium means 'many feet', alluding to its branched rhizomes; glycyrrhiza translates as 'sweet root'.
This plant is well adapted to our temperate rainforest. It dries out in summer when rain is scarce, but releases its leaves in the fall when there is more sunlight coming through the forest canopy.
Main photo by John Rusk, Berkeley, via Wikimedia Commons
Photo of fern growing on a bigleaf maple by brewbooks from near Seattle
Frond with spores photo by By USFWS - Pacific Region