This is largely restricted to Appalachian regions, but there are several disjunct populations in eastern states; it has recently spread from cultivation in N.Y. (Atha 2020). More good colls. of this species are needed to document the western extent of its range in Ky., where it is usually confined to steeper slopes and bottoms along larger streams. Reported colls. from CARL in far western Ky. (at MEM in SERNEC 2020) and from Gallatin Co. in se. Ill. (K) remain dubious. Unverified historical data of Gm are included here as uncertain records (open dots). There are verified records from narrow western extensions: along the Ohio Rv. downstream to at least OLDH and in adjacent se. Ind.; along the Kentucky Rv. downstream to at least ANDE; and in the Green Rv. watershed downstream to at least HART. Within these extensions, there is some evidence of introgression with glabra; see notes under that species. Both species may have similar sizes, growth rates and shade tolerances. Both glabra and flava vary in pubescence and in green-versus-pale color of lower leaf surfaces; but flava in Ky. generally appears to be pale or glaucous.The effects of mammalian herbivores on flava remain poorly documented, but, like glabra, this species appears to be generally avoided by deer (Atwood 1941, Kniowski 2016). A. flava is often considered a species of older growth with less disturbance, and it tends to become relatively tall in deep woods; however, regeneration from seed may be concentrated in canopy gaps, perhaps with more deer browsing (pers. obs.). The state champion is in CASE: 121 cm dbh, 42 m tall and 15 m wide (KDF 2020).