That's amazing! Thanks everyone for the quick ID. The nursery I bought from, did sell Chamaeranthemum gaudichaudii. http://blackjungleterrariumsupply.com/Chamaeranthe… So it makes sense that it hitchhiked in as a seed... and now I have lots of them! I'm very pleased. The internet does not say much about this species, except that it's native to Brazil. And thanks for the kind words about my terrarium. It's not actually that pretty!! It's kind of dirty and gross. :-) Dennis in Cincinnati (very pleased to have the mystery solved!)