Abstract: Bicyclic imides of formulae (I) and (II) and their agriculturally-suitable salts, are disclosed which are useful for controlling undesirable vegatation, wherein G is O or S; n and m are each independently 0; 1; 2; or 3; provided that m+n is 2 or 3; q is 1 or 2; X is CH.sub.2 ; CH(halogen); CF.sub.2 ; CHOCH.sub.2 F; CHOCF.sub.3 ; CHOCH.sub.2 CF.sub.3 ; O; S(O).sub.0-2 ; NH; N(C.sub.1 -C.sub.4 alkyl); or N(C.sub.1 -C.sub.4 haloalkyl); and R.sup.1. R.sup.2, and Q are as defined in the disclosure. Also disclosed are compositions containing the bicyclic imides of formulae (I) and (II) and a method for controlling growth of undesired vegetation comprising applying to the locus to be protected an effective amount, of the bicyclic imides formulae (I) and (II).