PLANT: Annual or perennial herbs or shrubs, glabrous to canescent, the hairs branching; stems erect to spreading, branched. LEAVES: simple, ovate, toothed, usually petiolate. INFLORESCENCE: dense axillary cymes or verticils. FLOWERS: sessile or pedicillate; calyx tubular, usually 10 veined, enlarging slightly in fruit, 5 toothed, the teeth subequal and acute to acuminate; corolla zygomorphic, tubular, blue purple, exserted from calyx, 2 lipped, 5 lobed, the two upper lobes united nearly to the apex, the side lobes reflexed, the lower lobe saccate and retaining the anthers until explosively released; stamens 4, paired, declining towards lower corolla lobe, the anthers of 2 connate cells with none abortive; style glabrous, the stigma evenly or unevenly 2 lobed. NUTLETS: oblong, smooth or rough. NOTES: Ca. 400 spp., tropical and temperate Amer. and Afr. (Greek: resupinate or turned back, referring to saccate corolla lobe). REFERENCES: Walters, Gretchen M. 2003. Lamiaceae J. Ariz. - Nev. Acad. Sci. Volume 35(2).