I'll take a wild stab at this one... based on the description, it sounds like you might have Datura stramonium or what is commonly called Jimsonweed. It's in the Nightshade family and is poisonous, so I'd use caution if this is indeed Jimsonweed.

I've included a link to a photo:

Hope this helps!
Shannon

Here is a link that might be useful: Link that might help

Could be an oak, with a "spikey ball" that is a gall (often formed by a wasp laying its eggs) on it.

Google for oak galls and wasps, and see what interesting forms that they take.

Sounds like purple datura to me. I only grow the white ones now. At least, on purpose. Ditto on the poison issue, please be careful!

Looks like Datura to me - spreads rampantly, at least in my yard, extremely hard to get rid of, and poisonous to boot. Unless you have ALOT of room and NO kids in the area, I'd dig it up and throw it away, and keep digging every time a new one pops up.

Just a note of clarification, the photo I posted IS Datura and I posted it for Philmont to see what Datura looked like and compare to the plant in question.

Shannon

Well lets see, If there are any flowers, what color are they? This could be indeed a moonlily plant in the ball with spikes are millions of tiny seeds. I've never heard of this plant being poison. So google moonlily and see if this is what your plant looks like. Also I go great lengths to grow them every year and they smell great when they bloom at night.