Spend time exploring wet areas in southern New England, and you will likely find a colony of Coastal Sweet-pepperbush (Clethra alnifolia). This plant -- also called Summer Sweet -- is known for its strongly fragrant summertime flowers and is easily recognized any time of year by its persisting fruit clusters. The rounded capsules are short-stalked and arranged on an unbranched stem.
To shore up your field identification, check for gray/brown twigs and terminal buds that look something like this:
Winter may not be the time to enjoy the scent of this native shrub, but identifying a colony now ensures that you'll know where to find it in bloom next summer. And even if you don't find one by then, perhaps you'll sniff out this shrub's location when the time is right.