Data Views Total Plants: 1 CSV Excel PDF Click on column headings to sort table by that column Plant Part Low PPM High PPM StdDev *Reference Arctium lappa Plant -- -- Pedersen, M. 1987. Nutritional Herbology. Pederson Publishing. Bountiful, Utah. 377 pp. *Unless otherwise noted all references are to Duke, James A. 1992. Handbook of phytochemical constituents of GRAS herbs and other economic plants. Boca Raton, FL. CRC Press.