Kilayim (“Mixtures”) is a tractate in Seder Zeraim (“Order of Seeds”) that discusses biblical prohibitions of mixed species, based in Leviticus 19:19 and Deuteronomy 22:9-11. These include planting certain mixtures of seeds, grafting different species of trees, growing plants other than grapevines in a vineyard, crossbreeding animals, working certain animals together, and mixing wool and linen in clothing..