I'm clearing some bushes out my backyard and found these awful prickly plants. They look to be part of a bigger plant that isn't prickly and have sent runners out all over. I'm trying to id them so I can figure out how best to eradicate them.
Rosa Rugosa I've added a pretty informative site. We sold these plants at all the nurseries I've worked or known. They are invasive, yes they are, birds eat the hips and poop them out. Easiest thing to do is PULL them out using gloves of course. When ever you see a newbie start come up cut it off. This will effectively starve the Rosa rugosa out...just be vigilant for baby plants. Best time to eradicate is to pull baby plants before they become a gnarly underground network.rosa rugosa
Make incredible hedges that bad guys and robbers will not be able to penetrate?
That looks like rose growth, most likely off a rootstock; possibly the grafted part of the original rose has died and now just the root stock is left and spreading everywhere. It's entirely separate from the plant or tree with smooth trunks mixed in with it. Which is difficult, because it will be next to impossible to extract all the roots and runners because they'll be mixed in with the tree/shrub roots.
If you do not want to remove the smooth stemmed plant, then you need to dig around a bit to expose the top of the roots of the rose, cut down the topgrowth and treat the roots and lower stems with a brushwood/tree stump killer. If you don't mind taking out the other shrub, then grub them both out, but expect the roots of the rose to be widespread as well as going down deep in the ground.
Rugosa roses are characterized by rugose leaves, which means deeply creased. They have heavily etched veins in their leaves. That looks more like a hybrid spinosissima Rose, and may have been a desirable ornamental. They do spread by suckers, however. Without seeing the flowers, it is impossible to ID The cultivar to know exactly what it was. I would have suggested a wait-and-see approach. I don't know what the smooth bark belongs to, but it's conceivable that it was the plant that invaded that flower bed, and not the rose.