Texas Bullnettle

I found this about two weeks ago when it had little buds on it, so I waited another week and snapped a picture with open flowers. At first I thought it looked like a wild melon or squash plant, just the way the plant spread over the ground. If you've ever seen a pumpkin vine, the way this sits is a lot like that. This is definitely different, but it's reminiscent of pumpkin.
I only found out what it was while attempting to identify something else. There are only so many variations on "spiky, thorny, prickly, white flowered, needley, Texas plant" you can try on Google before giving up.
Yes, it is as bad as all that makes it sound.
Texas Bullnettle is something you never-ever-ever want to touch. All those white dots you see in the pictures are "hairs" but are also known as "vicious glass-like needles." Those needles will break off, attach themselves in your skin, and release a toxin into you that causes a severe burning reaction that lasts around 45 minutes. This is an allergic reaction so for some people it can last days.
But onto the identification. They are between 1-3 feet high with several stems branching out of one root. The leaves are five pointed, crumpled looking, 2-4 inches (length and width both), and alternate on the stem. They have thick stems that are the most needley part of the whole plant, if broken it will ooze a milky sap. The white flowers are about an inch wide when open and are okay to touch, they usually have 5 sepals but can have 7 (no petals). The seeds are held in four separate pods that are attached together and are about 1-1.5 inches tall; they're not round, they have 4 vertical indents.
Every bit of the plant is covered in the .5 inch needles.
I'd repeat that you shouldn't touch them, but if you have eyes that work and half a brain if you saw one I think you could figure that one out yourself. I, on the other hand, decided to pull out a thick rag to attempt to bring some back with me. Me and my 2/5 of a brain learned better when the rag was easily punctured without me even pushing on it. I escaped unscathed.
All that said, apparently the seeds taste great and are good for you... if you can get to them.