Data Views Total Plants: 201 CSV Excel PDF Show All Paginate , Previous1..234567891011 Click on column headings to sort the list on the column Plant Part All parts ... Bud Bulb Flower Fruit Fruit Juice Herb Leaf Plant Pollen Or Spore Rhizome Root Seed Shoot Sprout Seedling Tissue Culture Tuber Low PPM High PPM StdDev *Reference Harpagophytum procumbens Root -- -- * *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.