Kilayim, Chapter 2, Mishnah 11
Kilayim, Chapter Two, Mishnah Eleven
Our mishnah discusses whether stalks of one species that lean over stalks of another species constitutes kilayim.
1) Stalks of grain which are leaning over other stalks of grain, or vegetable [plants] on other  vegetable plants, or stalks of grain over vegetables plants or vegetable plants over stalks of grain, all this is permitted, except in the case of the Greek gourd.
2) Rabbi Meir says: also in the case of the cucumber or Egyptian beans. But I recognize their words [as more acceptable] than mine.
Section one: In the case referred to in this mishnah, the person properly distanced the different species one from the other. If the stalks grew or the vegetable plants grew and began to hang over the other species, this does not constitute kilayim, since he distanced them properly.
The only except is the Greek gourd, which evidently can significantly tangle itself up with other species that are growing near it. Since this will really look like kilayim, he must uproot either the gourd or the other species growing near it.
Section two: Rabbi Meir adds two other species that also entangle themselves up with other species growing near them. However, in the end, Rabbi Meir admits that the rabbis limiting this to the Greek gourd is more acceptable than his extending it to the cucumber and Egyptian beans.
One might ask: if he tends to agree with the other rabbis, then why does he still make his statement at all? The answer, according to commentators, is that he received his opinion from his teachers, and although he did not actually agree with this opinion, he still stated it in order that it should be preserved for future generations.