This is widely scattered across southeastern states, but concentrated in swampy woods, especially on gradual transitions to adjacent drier ground. It extends north into upper sections of the Green and Cumberland Rivers (Meijer et al. 1981), and around the western Bluegrass region onto old glacial flats of se. Ind. Records from the eastern Knobs remain unverified. Both michauxii and montana have relatively large acorns (usually 2.5-3.5 cm long versus 1.5-2.5 cm in bicolor or 1-2 cm in muehlenbergii), but cups of michauxii have less appressed, more tuberculate scales, distinct to base (versus laterally connate in montana). The epithet prinus has been applied to michauxii by many authors; but see notes under montana. Leaves of michauxii are sometimes confused with montana or muehlenbergii, especially in the shade, where muehlenbergii is often much less densely stellate-hairy than in the sun. Introgression with muehlenbergii has been suggested (CW), but montana may be closer and has somewhat intermediate pubescence; see notes under montana. Compared to muehlenbergii. well-developed leaves of michauxii (like montana) tend to have more rounded teeth (versus acute to hardened projections), larger average size (ca. 10-28 x 5-18 cm versus 5-15 versus 4-8 cm), more consistently obovate shape (versus often lanceolate to oblong), and more gradual narrowing at the base (versus broadly cuneate to rounded). Lower surfaces have largely erect felty hairs with mostly 1-4 rays (versus more appressed stellate hairs with 6-10 rays), and tend to be less whitish-glaucous, even in sun. Upper surfaces tend to be less glossy, with more impressed tertiary nerves that are clearly visible with transmitted light. Well-developed winter-buds of michauxii and montana are relatively large: (3) 4-6 (7) mm long versus 2-4 (5) mm in alba, muehlenbergii and bicolor. See FNA 3, Stein et al. (2003) and W for more details.