clubroot, disease of cabbages, turnips, radishes, and other plants belonging to the family Cruciferae (mustard family). It is induced by a plasmodial slime mold that attacks the roots, causing, in the cabbage, undeveloped heads or a failure to head at all. Clubroot can be partially or in some cases completely controlled by the application of lime (if the soil is very acid), by rotation of crops, and by soil sterilization. The disease is also called finger-and-toe from the swollen shape it gives to roots. Plasmodial slime molds (phylum, or division, Myxomycota) are classified in the kingdom Protista.