Data Views Total Plants: 182 CSV Excel PDF Total Activities: 20 , Previous12345678910 Show all rows. Paginate rows. Click on column headings to sort table by that column Plant Part All Bark Bulb Flower Fruit Inflorescence Leaf Pericarp Plant Rhizome Root Seed Shoot Stem Tissue Culture Tuber Low PPM High PPM StdDev *Reference Zea mays Root -- 36.0 -0.4 * Zea mays Shoot -- 85.0 -0.7 * *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.