The Seven Sisters Oak is the largest certified southern live oak tree. Located in Mandeville, Louisiana, it is estimated to be up to 1, years old with a trunk that. species, and the tree appears to be an alternate type. Oak and hickory trees hybridize readily and the A few Louisiana tree species have leaves almost. In South Louisiana, live oaks are heritage, heirlooms, and history all rolled into one. More than any other tree or physical aspect of the.