Attack of the Weeds!

There is an unidentified weed that grows in my backyard. before we had it landscaped, it had overtaken an entire side of our yard. I had no idea it's stranglehold on my yard until now. It is actually a pretty weed. It has purplish greenish leaves. But it is very deceiving. Beneath the pleasant looking petals are the most insane, disgusting tree like roots I have ever seen. I mean one weed may have a trunk root that's close to 5lbs in weight. It's insane! And i'm obsessed with obliterating it. I have dreams about how to destroy it. It's like the day of the triffids:

I will figure out a way to destroy it!