Acanthus species; bear's breech

Whether you want to remove them is up to you. They are ornamental. However, some of the species get quite large in size. The main problem people encounter when trying to remove these plants, it that they can resprout from even tiny pieces of roots left in the ground. Some gardeners have resorted to sifting the soil after removing the parent plant, to limit those returns. Depending upon the growing conditions, complete removal might not be an easy task.

Bear's Breeches can be a lovely, dramatic plant in the right place. Needs lots of room. I had one volunteer in just the right place that needed something big to fill up the space. I love it.