Looks like a chinkapin, Castanea spp. Pod is maybe an immature nut? Did it come from a fuzzy or spikey husk?

The pod was attached right to a stem like you see in the picture. it is empty but for some yellowish dust stuff.

Then 'taint a chinkapin...

The pod could be a gall. Would help to see more of the plant. From the leaves visible it looks like Rhus.

Has it ever flowered?

This post was edited by jeserfen on Mon, Aug 11, 14 at 18:07

I am attaching two more pics. One is of a runner baby, and the other is a large group. You can actually see the line of how far the plant used to go into my lawn. It has never to my knowledge flowered, and I looked for more pods but couldn't find any. Happy to take more pics upon request.

This is a 'grove' of them. Used to be many more but I chopped/dug them out.

Looks like sumac. If the stems are hairy, probably Rhus typhina.

The problem with Rhus is that the original plant pic has alternate foliage, as the most recent pics do not. Rhus is opposite, as are the last pics, which do look like Rhus. Rhus also has a different seed head. I think we have two different things going here. Look at the first pic - alternate.

This post was edited by hortster on Mon, Aug 11, 14 at 20:12

While I am open to an alternative ID, I googled sumac gall and found something quite similar

{{gwi:315679}}

Another image of a gall also shows some leaves with alternate leaflets

{{gwi:315680}}

So sumac is both alternate and opposite, apparently.