Maasrot, Chapter Four, Mishnah Six
In todays mishnah Rabban Gamaliel, Rabbi Eliezer and Rabbi Akiba debate which parts of various plants must be tithed. Again, the general principle is that whatever part one is going to preserve in order to eat is the part that is liable for tithes.
1) Rabban Gamaliel says: shoots of fenugreek, of mustard, and of white beans are liable [to tithe].
2) Rabbi Eliezer says: as for the caper bush, tithes must be given from the shoots, the berries and the blossoms.
3) Rabbi Akiba says: only the berries are tithed since they [alone] count as fruit.
Section one: According to Rabban Gamaliel one will eat the shoots of these various plants; therefore they are liable for tithes.
Section two: Rabbi Eliezer holds that three parts of a caper bush must be tithed, because they all are eaten. Rabbi Akiva says that only the capers must be tithed because they are the most valuable part of the bush, the part that is primarily eaten.