This species of lowland woods is poorly known in much of its largely midwestern range, and it has often been confused with frondosa or sylvatica. Varied characters have been used to distinguish these taxa (compare F with FNA 25). Records of bushii are concentrated in and around Mo. and Okl., scattered through s. Ill., s. Ind. and w. Ky.., then disjunct rarely in Atlantic states from Md. to Ga. (FNA 25; W). M. frondosa appears to be the closest species; both may differ from other woodland species as follows (F, Y, W; FNA 25): lateral inflorescences usually abundant, without distinct stalks and enclosed in the sheath (versus absent or distinctly stalked and exserted); internodes glabrous or slightly scabrous below nodes (versus glabrous or distinctly puberulent below nodes). M. bushii differs from frondosa as follows: glumes 1.4-2.0 mm long (versus 2-4+ mm), ca. 50-70% as long as floret (versus 75-100%); ligule 0.2-0.5 mm long (versus 0.8-1.5 mm); leaf blades of lateral branches often distinctly smaller than those of main branches (versus similar in size); other reported vegetative differences (F) need further assessment. M. bushii is reported to occur generally further from active floodplains and sometimes on relatively dry uplands (Y). Plants mostly have short awns or none, but long-awned plants may predominate locally in Ky. (and perhaps south to Miss.), where there has been some confusion or intergradation with the awned variant of frondosa treated here under the name commutata. The only colls. from Ky. that clearly match typical bushii may be from BALL (MUR) and LYON (APSC). The species was also recently collected for the first time in Tenn. by E.W. Chester (pers. comm.; from Stewart Co. for APSC).