Acifluorfen tolerance charateristics determined the involvement of absorption, translocation, and metabolism in acifluorfen tolerance. Less than 6% of the applied 14C-acifluorfen was absorbed. There were no differences in acifluorfen absorption between susceptible and tolerant somaclones. More 14C-acifluorfen was translocated in the susceptible than the tolerant somaclones. The susceptible somaclone did not metabolize acifluorfen while some somaclones (i.e.,EBN-3A) metabolized 14C-acifluorfen. Nomenclature: Acifluorfen, 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid; eastern black night shade, Solanum ptycanthum Dun.,#3 SOLPT.