suber

When the tree is some five years old, its whole energy is directed toward the increase of the suber.

But such a thing is rarely allowed to happen: the suber is of too much value to man.

In one species of oak this layer--which is called the suber--assumes a peculiar character and is of remarkable thickness.

That the suber of the Romans was our cork-tree, is generally and with justice admitted.

This name is as much of a mystery as the word “Suber” and its origin can only be guesswork.