1. Flowers at least partly (except on depauperate plants) in multiple dense axillary whorls; corolla yellowish (pale pink to purple in the rare waif M. citriodora), dotted with darker purple, the upper lip strongly arched.

2. Corolla yellowish, dotted with purple throughout; bracts subtending floral whorls white (fading to dull pink in fruit)

M. punctata

2. Corolla pale pink to purple, with darker purple flecks mostly in the throat; bracts subtending the floral whorls purple.

M. citriodora

1. Flowers all in terminal heads at ends of main stem and branches; corolla white, bluish, purplish, or red, little or not dark-dotted, the upper lip ± straight on top at maturity.

3. Corolla 31-45 mm long, bright red, the upper lip glabrate (especially toward tip) or sparsely pubescent; calyx glabrate at throat (summit of tube within); bracts tinged with red.

M. didyma

3. Corolla less than 30 mm long, lavender to white, calyx densely bearded at throat (the hairs conspicuous between the teeth); bracts usually greenish.

4. Upper lip glabrous to ± pubescent, but hairs at the tip, if present, no longer than the rest.

M. clinopodia

4. Upper lip densely pubescent with a sparse to dense tuft of long, white hairs at tip.

M. fistulosa