Data Views Total Plants: 21 CSV Excel PDF , Previous12 Show all rows. Paginate rows. Click on column headings to sort table by that column Plant Part All Fruit Leaf Seed Shoot Stem Low PPM High PPM StdDev *Reference Vigna unguiculata Seed 0.21 2.4 * *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.