Reference for Shabbat 135:2

They said an important general principle with regard to the sabbatical year: anything that is food for man or beast, or a species [of plants] used for dyeing, and cannot be left growing in the soil, the law of the sabbatical year is applied both to it and to its money substitute and the law of removal applies both to it and to its money substitute. Which are they? The leaves of the wild luf, the leaf of ceterach, endives, leeks, portulaca, and netz hahalav. What is the food for cattle? Thorns and thistles. What is species of dyeing matter? Aftergrowths of woad and madder. The law of the seventh year applies both to them and to their money-substitutes and the law of removal applies both to them and to their money substitute.

And they said yet another general principle: Anything that is food for man or beast, or is used for dyeing, but can be left in the soil, the law of the sabbatical year applies both to it and to its money substitute but the law of removal does not apply to it or to its money substitute. Which are these? The root of wild luf, the root of ceterach, scolopendrium, the root of netz hahalav and buchreyah. What is the species of dyeing matter? Puah (madder) and reseda. The law of the sabbatical year applies both to them and to their money substitute but the law of removal does not apply to them or to their money substitute. Rabbi Meir says: their money substitutes must be removed by Rosh Hashanah. They said to him: since this law does not apply to the plants themselves, all the more so it does not apply to their money-substitute.