Data Views Total Plants: 21 CSV Excel PDF Total Activities: 2 , Previous12 Show all rows. Paginate rows. Click on column headings to sort table by that column Plant Part All Flower Fruit Fruit Juice Inflorescence Leaf Plant Seed Stem Pt Low PPM High PPM StdDev *Reference Zea mays Seed 1.1 3.5 -0.3 * *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.