These plants have been provisionally named M. serotina by R.T. Simmers (pers. comm). Based on initial revision, they are most frequent west of the Appalachians (Ala., Ky., Ill., Ind., Mo., Ohio, Tenn.), but also scattered further east (D.C., Del., Md., N.C., Pa., W.Va.). D and St treated these plants as a somewhat indistinct, broad-leaved form of fistulosa, generally intermediate between fistulosa and clinopodia, with probable hybrid origin. Compared to clinopodia, corollas are flushed with pale pink to purple or red, often without distinct spots (whitish with distinct red/purple spots on lower lip); calyx lobes tend to have broader triangular bases, usually with 5-10 distinct large pustulate, short stipulate to sessile reddish glands (versus not so), and with some distinctly long hairs on the surface not just in the throat (versus not so); plants have scattered to dense long hairs on stems, especially at nodes, and on lower leaf surfaces, especially along veins (versus mostly glabrous); leaves usually plain to yellowish green (versus more or less bluish-green), with little difference on lower surfaces (somewhat paler or more glossy), except for distinctly broad, yellowish midribs and primary veins (with relatively narrow, indistinct midribs and primary veins); flowering usually in mid to late July (late May to mid-July); plants typical of somewhat disturbed edges of forest, especially along larger floodplains or pathways (versus ravine or montane forest with relatively little disturbance). In contrast to fistulosa, most colls. are from relatively mesic woods and edges on lowlands. Mid-cauline blades are usually (2) 2.5-4.5 (5.5) cm in breadth (versus 1-2 cm), widest about a third from the base (versus a quarter), relatively deep green, and on longer petioles (usually 2-3 cm versus 0.5-2 cm). Lower surfaces have scattered spreading hairs, longer (generally 1-2 mm versus <0.5 mm) and not as dense, compared to fistulosa var. mollis. Stems are mostly glabrous and glaucous. Corollas are paler pink at tips to almost all white (versus more uniformly deep pink-purple), and usually less hairy; the apical beard of hairs on the upper petal (lip) is usually indistinct or absent; and the calyx orifice is usually less hairy. Flowering of fistulosa in Ky. and Tenn. has more varied dates, from late Jun to Aug, but with a peak in late Jul, usually startng later than sympatric "serotina".