Growing beside the road, I took a rooted piece to my lodgings to photograph, planted it in a pot and it recovered and grew amazingly fast! The whole plant has a waxy and succulent feel and look.
Anyone has an idea? I think it is attractive enough for someone wanting it in their garden..

I would say Portulaca umbraticola

Certainly a Portulaca Ron, there are 7 native species in the Rio de Janeiro state, I'll do further search..

I think Portulaca umbraticola is the closest match and it is present in the area I was in, according to the 'Flora do Brasil' !