yes, I've regularly bought lemongrass in Belgrano also - they always seem to have it at the huge supermarket on Mendoza, around the corner from Arribeños (I think it's called Asia World or something like that).
the Carrefour on Vicente Lopez, entre Rodrigues Pena and Montevideo has it....AT times, ojo on the at times! and you have to look for it floating around near the ready made salad packs etc...i've ALWAYS found it in Barrio Chino!
I was looking for it in Barrio Chino there a few days back, couldn't find it. Anyone been buying it recently and know where it can be definitely found. Also looking for galangal and kaffir lime leaves if anyone has any ideas. Looking to make some thai curry pastes