This unlobed relative of tripartita is centered in Appalachian regions, and may be most common on the Cumberland Plateau, but it also occurs in the Southern Appalachians and some disjunct localities on the Interior Low Plateaus. Ballard et al. (2023; W) has recently revived its status as a species rather than a variety of tripartita. V. glaberrima is much more frequent than tripartita sensu stricto in Tenn. (Ch), Ky. and Ohio (D. Boone, pers. comm). There has also been confusion (e.g. in B) with pubescens or eriocarpa, which are usually more robust plants with upright or spreading growth forms; hybrids are suspected in a few cases and mapped as open circles. Compared to pubescens and eriocarpa, glaberrima is a strictly upright plant with solitary stems (versus 1-several, erect or decumbent); it has cuneate to truncate bases on upper cauline leaves (versus more or less cordate in pubescens); and most blades have L/W ca. 1.5-2 (versus ca. 1), with acuminate apex (versus rounded, acute or abruptly short-acuminate) Also, basal leaves are usually lacking on flowering stems (versus often two or more in pubescens); its leaves are generally deeper bluish green and less closely serrated. Klaber (1976) noted and illustrated "running stolons" that are not known in pubescens. There are no clear differences in flowers or fruits, but further analysis is needed. V. glaberrima typically occurs in the transition from mesic to subxeric woods on medium acid soils; such habitats are intermediate between those of eriocarpa and hastata. Hybrids were unknown to Ballard et al. (2023), but the coll. from TRIM (KY) suggests intergradation with eriocarpa.