Data Views Total Plants: 2 CSV Excel PDF Click on column headings to sort table by that column Plant Part All Rhizome Seed Low PPM High PPM StdDev *Reference Chenopodium quinoa Seed -- 1000.0 Jim Duke's personal files. Panax japonicus Rhizome -- 1900.0 * *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.