[If] one preserves three [kinds of vegetables] in one barrel — R’ Eliezer says: One may eat based upon [the availability of] the first. R’ Yehoshua says: Based even upon the last. Rabban Gamliel says: Any vegetable whose species has disappeared from the field must be removed from the barrel; and the halachah follows his view. R’ Shimon says: All vegetables are alike regarding [the law of] biur. One may eat purslane until artichokes disappear from the valley of Beis Netophah.