I wasn't saying it was that one in the last link Myriam, only a possible Zornia species as there's several of them but nothing else comes up in a search. I've been through many of the genera in Fabiaceae but my computer is sometimes 'not responding' so I'll have to go do something else for now.
I got somewhere around the P's, I've looked at may different generea in Fabaceae and nothing else looks close.
The leaves on some pea family is sort of waxy, garden pea leaves are a little like that. I really doubt it belongs to another family but I could be wrong.