Hitchhiker with Isabelia virginalis
 

Does anyone have any idea what this plant might be? (See attchment.) It came to me on an Isabelia virginalis from a vendor if Ft. Myers, FL

I believe the Isabelia had been imported (presumably from Brazil) shortly before I bought it. On the other hand, There's a smaller seedling just sprouted in the sphagnum that this sits on.

Sorry for the bad focus. If you're not familiar with american coinage, that's a dime, about 1.5 cm across.

This looks to me like Artillery plant (Pilea microphylla).
I had one hitch a ride on my pitcher plant that was about the size of yours and had already thrown out seeds into 2 neighboring pots.
I still see it sprout in those pots every now and again.
A Google search shows it is considered an invasive species in Central America, but I also see it grows in Florida and can be used as ground cover or in a terrarium.
I pull it out of my pots when I see it.

I have lots of that stuff in my pots, I pull it out when I can, but it tends to break off so comes back. Definitely weedy. No doubt it hitchhiked in some plant, but it loves California... grrrr.

I've even seen it naturalize in Arkansas. Pretty tough (through reseeding).

Thanks everyone. I think it's definitely Pilea microphylla.

Roberta, my collection is nowhere near as large as yours. I'm going to keep it for the moment -- just to see. (Despite all the scary press.)

It especially likes baskets (which lots of my plants do too) It doesn't seem to hurt anything, doesn't choke off orchid roots or anything like that. Just aggressive. So keep it confined and you'll be OK.

This stuff grows all over my basement grow room. It is annoying but at least it smells nice (spicy) when weeding it out of my pots and trays.

Put some of it into a 1 gallon pickle jar terrarium with a jewel orchid and weed out all the rest.

I like the idea of containing it in a terrarium. You can enjoy it but it will not be able to spread.