Most New England beach-goers will readily recognize this plant as Beach Rose (Rosa rugosa). This shrub -- which undoubtedly has many other common names -- is not native to the US but is nonetheless well-established along the New England coastline. This plant doesn't just tolerate harsh, salty conditions, it thrives in them and produces fragrant flowers and delicious (and nutritious) large rosehips in abundance. The ripe raw hips, with ends trimmed and seeds removed, taste to me like a cross between a cherry tomato and a plum. I like them very much.
December update: Gone are the plump hips of a few months ago, but these dried beauties would still make a delicious and nutritious tea.