pics are a bit out of focus. First glance they look like rosebay, but the massive underground root suggests perhaps not. The other possibility is one of the euphorbias - probably Euphorbia griffithsii. It will have no flowerheads at theis time of year, just shoots, and it spreads by thick underground roots. If it is that, it's worth keeping - it has flowers surrounded by showy orange bracts which last for a long time.

If you haven't got other plans for that area, I'd suggest letting at least some of it grow for another couple of months until it flowers and you get a firm id.