ear leaves --25b.

29c. Flowers in many-flowered whorls, which are axillary or terminal, or
aggregated into terminal spikes or racemes --31.

30a. Corolla yellowish =Giant Hyssop, Agastache nepetoides.=

30b. Corolla purplish
=Giant Hyssop, Agastache scrophulariaefolius.=

31a. Corolla distinctly irregular, the lower lip longer than the upper
--32.

31b. Corolla almost regular, the lobes nearly uniform in size --35.

32a. Stem-leaves sessile or very nearly so (flowers blue) --33.

32b. Stem-leaves long-petioled --34.

33a. Leaves linear-oblong, acute at both ends (3-8 dm. high; summer)
=Hyssop, Hyssopus officinalis.=

33b. Leaves oblong to ovate, rounded at the ends (2-4 dm. high; late
spring) =Bugle, Ajuga reptans.=

34a. Leaves ovate to oblong, acute; flowers pink, white, or pale
purple (6-15 dm. high; summer) =Catnip, Nepeta cataria.=

34b. Leaves nearly circular or kidney-shape; flowers blue
(creeping; flowers in spring and summer)
=Ground Ivy, Nepeta hederacea.=

35a. Flowers in terminal spikes, or the lower axillary (3-8 dm. high;
flowers pink-purple or white, summer) (Mint) --36.

35b. Flowers all in axillary whorls (flowers pink-purple or white,
summer) (Mint) --38.

35c. Flowers in terminal capitate corymbed clusters (4-8 dm. high;
flowers white or dotted with purple, summer) (Mountain Mint) --41.

36a. Leaves sessile or with very short petiole
=Spearmint, Mentha spicata.=

36b. Leaves with manifest petioles --37.

37a. Principal leaves less than half as broad as long
=Peppermint, Mentha piperita.=

37b. Principal leaves more than half as broad as long
=Bergamot Mint, Mentha citrata.=

38a. Stem glabrous; leaves ovate to obovate (4-8 dm. high)
=Downy Mint, Mentha gentilis.=

38b. Stem pubescent, at least on the angles (1-6 dm. high) --39.

39a. Principal leaves distinctly petioled and somewhat rounded at base
=Wild Mint, Mentha arvensis.=

39b. Leaves tapering to the base --40.

40a. Leaves and stem pubescent