Peah, Chapter 7, Mishnah 1. This mishnah deals with cases in which the law of shichechah (forgotten produce) does not apply - where something that was forgotten is not considered forgotten at all. The Rambam, in Hilchos Matnos Aniyim, sums up the criterion: something is considered shichechah only when there is no way for the owner to remember it unless he happens upon it again. But something well known and famous, which does not easily slip from the mind, and which the owner is bound to remember on his own - is not included in shichechah. For example, a famous tree, as the mishnah will detail.
The text of the mishnah:
"Kol zayis sheyesh lo shem basadeh" - any olive tree that has a known name in the field, and people recognize it. It need not specifically be an olive tree, but apparently this phenomenon was more common with olive trees. "Kazayis hanetofah bish'ato" - like the well known olive tree in the place called Netofah, in its time, during the period when it was famous. (It is worth noting that the version "afilu kazayis hanetofah" is inaccurate, and one should not read "afilu.") "Ushcheicho - eino shichechah" - even though he forgot to harvest it, it is not considered shichechah, since the owner is bound to remember it on his own: "What became of the Netofah olive tree? I need to go back and take it."
The three markers by which the olive tree is known:
The mishnah asks "Bameh devarim amurim" - in what case is this said, and answers: "Bishmo uv'ma'asav uvimkomo" - by its name, by its yield, or by its location, and it gives an example of each one:
"Bishmo" - by its name: "Shehayah shifchoni o bishani" - that it was a "shifchoni" or a "bishani." Shifchoni, from the word "shofech" (pours), as though it pours out oil from its abundance of fruit; bishani, that it shames (mevayesh) the other trees with its abundant yield. A tree known by such a name is famous, and is not considered shichechah.
"Bema'asav" - by its yield: that it produces a great deal, bringing forth much fruit and much oil, and therefore it is not forgotten.
"Bimkomo" - by its location: that it stands beside the winepress or beside a breach in the wall.
It is worth noting that in the previous chapter we learned that according to Beis Hillel, a sheaf lying beside a wall and the like is still considered shichechah, and the mere fact that it is next to a distinctive landmark does not remove it from the category of shichechah. This would seem to contradict what we have said here, but the commentators explain that in our case Beis Hillel agrees that it is not shichechah. The reason for the distinction: a sheaf is not attached to the ground and is liable to be moved from its place, and therefore its standing beside a particular object is not permanent and does not make it memorable; whereas an olive tree standing in a particular place is fixed there, and for that reason it is memorable.
Olive trees that are not famous:
The mishnah continues and rules that other olive trees, which are not famous, are subject to the laws of shichechah. Regarding them, the criterion depends on their quantity - as we have learned, once there is a certain quantity of something, it is no longer shichechah. Two olive trees that were forgotten are shichechah; three olive trees that were forgotten are already not shichechah, since that is too large a quantity to be forgotten.
The view of Rabbi Yose:
Rabbi Yose says that there is no shichechah for an olive tree at all. Every olive tree is important enough, and even if the owner forgot it, the forgetting is only temporary, and he will certainly remember it afterward. The Yerushalmi explains that Rabbi Yose said this with reference to a particular period in history, the time when Hadrian destroyed the land and olive trees were scarce. At that time, every remaining olive tree was something remembered and not forgotten, and therefore it was not subject to the law of shichechah. But in a situation where olive trees are plentiful, even Rabbi Yose agrees that there is shichechah for an olive tree.
In summary: In this mishnah we learned that the law of shichechah does not apply to something famous, which the owner is bound to remember on his own. An olive tree that has a name in the field - whether by its name, by its yield, or by its location - is not shichechah. In contrast, olive trees that are not famous are judged according to their quantity: two are shichechah, three are not shichechah. And in the view of Rabbi Yose there is no shichechah for an olive tree at all, and the Yerushalmi explained that his words were said with reference to a period when olive trees were not plentiful.