I don't know if it grows in Argentina too, but it is a Brazilian native tree.
Very dense and hard wood. It is frequently used in here for guitars, for backs, sides, bridge and fingerboard. On custom or industrial-made guitars.
If not correctly seasoned it tends to crack.
It's Brazilian name is "Pau Ferro", wich would translate as "Iron Wood". It is also known as Caviúna, but a lot of other woods are known as Caviúna as well...
This is a Santos Rosewood back/sides guitar from a local luthier I know:
http://store.guitanda.com.br/instrum...2010-sppf.html
Sonicaly speaking, it is known to have a dryer sound on classical guitars (never heard an acoustic with it), when used for back/sides, compared to other rosewoods (Brazilian, Indian, etc.).
Hope it helps.
Gustavo.