posted 10 years ago
its really difficult to tell the exact species of wild roses, they all look so much the same! and theres a lot of variability within each group, probably crosses of native and introduced wild roses.
big clues are from either the amount and kinds of thorns and also the way the hips are, if they are short and fat or elongated. but even with this theres a lot of variability. where you are located also helps, if you look up the most common varieties in your locale.
i would guess this is either the virginia rose (aka "prairie rose") or the dog rose, possibly the swamp rose. thats mostly because these are the most common ones, especially in the east and middle of the country.
out here, california has like seven different kinds ! so i have mostly given up with exact ID, though i have spent a while pouring over pictures and checking out the hips and thorns trying to get an ID. the only ones that i can clearly identify are the rugosa rose, which is really distinct. if you feel inclined you might be able to figure it out, look at the leaves. thorns and hips and look up the varieties for your area, this might work.