In J. R. R. Tolkien's fictional world of Middle-earth, the Brown Lands was a region across the Anduin from Fangorn forest. For a long time the Entwives worked in their gardens there. Later Sauron blasted the entire area and it was called The Brown Lands. Treebeard obviously was convinced that the Entwives were not all destroyed but were "lost". Their ultimate fate remains a mystery.
