Without volunteers wielding clippers and loppers, most trails in Princeton would quickly become overgrown. Some preserves, like Mountain Lakes, Herrontown Woods and Autumn Hill Reservation, have more organized maintenance, but in some others it's catch as catch can. In May and June, that first flush of growth begins reaching out over trails, and so a pair of clippers is handy to keep in the back pocket during a hike. Cutting back anything that overhangs a trail is useful, but as a botanist I'm also identifying as I go along. Most of the shrubs that grow out into trails are invasive species that we'd want to cut wherever they are growing, but especially along trails. There are also some natives, but I'll start with the non-natives, which are so numerous mostly because the deer won't eat them.
A common story about native plants in the wild: there's a native Euonymus, called Hearts-a-Bustin', but it's rarely seen because the deer love to eat it. We've nurtured a few specimens of it to show off at the Barden.
Bush honeysuckle -- Honeysuckle comes in the form of a vine (Japanese honeysuckle) and several species of shrub. it is frequently found along the edges of people's backyards--a sort of default vegetation that moves in on its own. It can also be numerous in some of Princeton's preserves.