A weed? Slim chance.

I have never grown them but assuming you used a sterile soil-less potting mix the odds are 90% that what is growing is a germinated milkvine seed.

On the other hand IF you have kept it too wet and it's exposed to the air then tiny fungus that appear to be like mushroom can germinate on the soil surface.

Google Images has tons of pics of it in various stages but I couldn't find one of it when just germinated. Sorry.

Dave

it was sterile soil and pots. it isn'tgrowing in any other container so i assume that pot did not get too much water. i can't find any in google either. i will take pictures of this germinated seedmfungus and see where it goes. maybe it is miilkvine. i saved half the seeds to give them to a florida or georgia extension office if it is indeed a rare species. Thanks for replying Dave.