Data Views Total Plants: 28 Show all rows. Paginate rows. Click on column headings to sort table by that column Plant Part All parts ... Bark Fruit Gum Leaf Plant Resin, Exudate, Sap Rhizome Root Seed Tuber Low PPM High PPM StdDev *Reference *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.