Ok , i read an entry in wikipedia.
http://es.wikipedia.org/wiki/Vaccinium ( i know you like bibliographical citations)
Vaccinium refers to a shrub.
It also mentions that arandano ROJO , is considered by some to be a completely different genus.
Color me amongst that group.
Regarding confusion caused by argentines naming things willy nilly.
I came to consult sources because i had the very same situation:
On my property , have had to clear some species of trees and plants that have grown as an invasive species, and were not natural to the original landscaping this property had.
Among them were what "informed" locals call Acacia Blanca , and Acacia Negra.
They are both trees , they are both rather green , they both have leaves , they both have spines.
Ony difference is that one is not an accacia at all . The latter is classified as pseudoacacia.
SO. one is great for firewood , one is great for fenceposts. understand where Im going ? Go buy firewood , go buy fenceposts , and what the gaucho will tell you is " es acacia" . The uninformed might buy it . If you are one that took it upon yourself to educate yourself on the issue , it would be more difficult for that fella to sell you " gato por liebre"