Are the leaves sort of mealy, and quite white/silvery on the undersides? Are there berries? If so I would guess some kind of Eleagnus. Often considered invasive but if that's what it is, it's a nitrogen fixer, fruit is more or less edible, and a good animal forage.....
Alder Burns (adiantum)
Location: Southern New Hampshire
posted 5 years ago
Yes about the silver leaves, no about the berries.
Probably Autumnberry (Elaeagnus umbellata), aka Japanese silverberry, autumn-olive and Russian-olive. It has edible fruit that appears in the fall. Highly invasive, it has become naturalized in many areas.