This uncommon species is centered in the central Mississippi Valley, typically in thin woods on clayey soils with summerl dryness and winter wetness. There are disjunct sites in e. Tenn., se. Ohio (Gardner et al. 2004), N.Car. and Va. (K, W). It can be confused with frondosa, and some records should be rechecked. M. glabriflora usually has glabrous lemmas; in contrast, other eastern species have hairy lemmas, at least near the base. Also, it has leaves that are relatively narrow (ca. 2-4 mm versus up to 7-8 mm or more in other species), firm and erect. Plants are rather bushy-brached, with axillary inflorescences that are partly included in sheaths, as in frondosa and bushii. Stem internodes are mostly glabrous and shiny, as in frondosa and bushii, though more scabrid to puberulent below nodes. FNA 25 indicated that the specific epithet should be "glabrifloris", but that spelling may be considered an orthographic variant; "glabriflora" was used by F, Cr, J and others. However, W has finally relented and followed FNA.