Related for Sukkah 66:7

A lulav, whether bound or not bound is valid. Rabbi Yehudah says, "One bound is valid, but one not bound is not valid." One must not tie it together on the day of the festival; but one can draw out a twig from it, and bind it. "They do not bind the lulav but with its own kind" - the words of Rabbi Yehudah. Rabbi Meir says, "It may be tied even with a cord." He also says, "There is a story of the men of Jerusalem, that they were binding their lulavs with gold bands." They said to him, "Do you seek a proof from this?" The fact is, they were binding them with their own kind beneath the gold bands!