The branch of a hadas which has been lopped off is invalid for use as one of the Four Species on the holiday of Sukkot, but if it were lopped off and grew again or if it fruited at the spot of the cut, it is once again valid for use. R’ Jeremiah asked: if a hadas is lopped off before the holiday of Sukot and on the holiday itself it fruited at the spot of the cut — is the hadas valid for ritual use? What are the issues under debate? On one hand, when the holiday of Sukot began the branch had not yet fruited at the spot of the cut, and so it was invalid for ritual use at the start of the holiday. Since it was invalid for use during part of the holiday, it should continue to be invalid for ritual use, even if it fruited. On the other hand, at this point of the holiday it is a hadas which is valid for ritual use. (The Talmud discusses this matter at length, as do many commentaries.)
(Babylonian Talmud, Tractate Sukah 33a)