This recently described segregate of clinopodia occurs is largely restricted to hills of the central Interior Low Plateaus in Tenn., Ky. and Ind. (Floden et al. 2026). It was recognized informally as "sororia" by R. Simmers in the 1980s. Together with austroappalachiana (Floden 2015), brevis (Weakley et al. 2017) and maxmedleyi (Floden et al. 2026), these taxa differ from clinopodia and its closest relatives as follows: style usually with hairs (versus glabrous); corollas more or less uniformly white to pink/purple (versus mostly white but maculate with purplish spots or unevenly flushed with pink); calyx lobes with 2-6 distinctively large stipitate/pustulate anthocyanic glands (in addition to any smaller glandular hairs); leaves generally narrower (mostly 1-3 cm versus 1-5 cm), and with petioles less than 2 cm (versus up to 3-4 cm); plants typical of subxeric to xeric open woodland and grassland (versus mesic to submesic or subxeric). In contrast to austroappalachiana, maxmedleyi and brevis, simmersii has calyx 7-9 mm long (versus up to 12 mm), the lobes mostly 0.7-1.1 mm long (versus 0.8-1.5 mm), usually green to stramineous (versus purplish); leaf blades mostly ovate (versus ovate-elliptic or lanceolate), mostly 2-4 cm wide (versus 0.5-2.5 cm), usually with sharp serrations mostly 1-2 mm deep (versus 0-1 mm), usually with long hairs on major veins below (versus more or less glabrous), upper surface usually dull, drying to greyish-green except for purplish midrib (versus often lustrous, deeper green); stems usually remaining greenish except for purple angles in full sun (versus often purplish throughout), the uppermost internode usually with punctate glands (versus lacking). A few colls. suggest hybridiization with fistulosa or maxmedleyi.