What is it and how do I get rid of it
There is something that is growing in my lawn that has woody stems and an underground jungle vine root system that is impossible to follow. I pull up some of one but it seriously like a web of intertwined vines underneath the grass. So 1. what is this nasty crap and 2. how do I get rid of it? TIA! Pictures are from last summer, but if needed I can take pictures of what it looks like now when it is first coming up. It has kind of a reddish/pink tassel like thing on top
It could be Japanese knotweed:
Or it could be wild plum which forms dense thickets by suckering:
We'd need better photos of various parts of the plant, especially the flowers, to do a better job identifying it. In either case, if you can't deal with it by hand, I suggest you use a broadleaf shrub herbicide such as triclopyr. You can use glyphosate to eradicate more completely, but that will do in your lawn, too.
I'm pretty sure what you are seeing are suckers from the tree. I'm not sure what the tree is, perhaps some species of Prunus (cherry or plum) or maybe alder (Alnus spp.).
In either case, the tree is causing the problem. Even if you took out the tree, the suckering would continue for years, although you could then use an herbicide on the suckers. However, if you wish to keep the tree and you use an herbicide on the suckers, you risk harming the tree. In this case, probably the most reasonable approach is to continue to mow them down.
Also, heavy suckering is often a tree's response to heavy pruning or injury. Read here: