You have comfrey there, which is extremely persistent and difficult to remove, though it will succumb to a herbicide like glyphosate.
On the other hand, the leaves can be soaked in water for a week or two and it makes a fabulous liquid feed for tomatoes and almost any other plant.

And the bees love the flowers. You can make a poultice with it to treat sprains too. To get rid make sure that when you dig it up you also dig the surrounding area quite deeply and examine each forkful of soil for bits of root - every bit left in will grow again. Then the following season watch the area closely and every time you see a bit growing do the same thing. It would be best not to plant much of anything else very near until it has all gone, which may take a couple of seasons. It is important to take out new growth as it appears before it has chance to throw out lots of long roots. The plant in your first photo will have sent out roots several feet away already. Glyphosate is easier of course, but I dig it out myself and am slowly winning.