Ragweed

Great Texas Ragweed Batman!
It's actually Giant Texas Ragweed, and I'm surrounded.
This one is IDed by it's leaves. About half of the leaves are three pointed and half of them are ovate. They grow oppositely on the thick woody stem, but can become alternating near the flowers. The leaves are a light silvery-grey and dull. The ovate leaves are serrated, the tri-pointed ones are actually just deeply lobed.
The plants can grow up to 4 feet (the pictured one is about that big) and have lots of flowers. The flowers are green and can bloom into fall, which they all seem to be doing right now; they grow on little stalks in clusters and look like tiny hanging bells.

If you're allergic to these buggers you probably know how to identify them already. If you're not allergic you should learn so you can rip them all out of the ground and burn them.