Data Views Exclude Ubiquitous Chemicals Activities: 127 Chemicals w/Activities: 14 All Chemicals: 21 CSV Excel PDF Previous12 Show all rows. Paginate rows. Click on column headings to sort table by that column # Activity Chemical Part All Bark Branches Leaf Root Bark Twig Wood Low PPM High PPM StdDev *Reference 22 22 MYRCENE Branches 104.0 120.0 * *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.