768 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



1. Functional stamens 4 (6). 



6. Calyx teeth 10, hooked at apex; flowers in dense subglobose glomerules; 



upper lip of the corolla deeply notched 7. Marrubium. 



6. Calyx teeth 5 or none (7). 



7. Teeth of the calyx none, the lips even and rounded; upper lip of the corolla 

 galeate, completely enclosing the stamens (8). 

 8. Entire calyx becoming enlarged and bladderlike at maturity, com- 

 pletely enclosing the nutlets 5. Salazaria. 



8. Upper surface of the calyx bearing a small appendage, this developing at 



maturity into an erect conspicuous flap, the calyx at maturity 

 separating into 2 portions longitudinally, the upper, flap-bearing 



portion deciduous 6. Scutellaria. 



7. Teeth of the calyx five (9) . 



9. Calyx enlarging into a flaring veiny funnel 2.5 cm. across; plant quite 



glabrous 14. Moluccella. 



9. Calyx enlarging to some extent but not as in Moluccella (10). 



10. Lobes of the calyx markedly unequal; flowers in dense oblong 



bracteate spikes (11). 



11. Upper calyx lip with the middle tooth ovate, twice as broad as the 



other teeth, all of the teeth spine-tipped; bracts spinose- 



toothed, hollylike 10. Moldavica. 



11. Upper calyx lip with the teeth completely joined to form a tri- 



cuspidate squarish lip; bracts ciliate, entire, clasping. 



11. Prunella. 



10. Lobes of the calyx sometimes unequal in length but otherwise all 



much alike, deltoid, lanceolate, or subulate; flowers in axillary 



clusters or forming interrupted spikes, less often in congested 



spikes (12). 



12. Hairs of the canescent calyx and foliage branched, intricately 



tangled; middle lobe of the lower lip of the corolla distinctly 



dipper-shaped; plant a shrub 24. Hyptis. 



12. Hairs simple; middle lobe of the lower lip of the corolla plane and 

 spreading or at most lightly cupped (13). 

 13. Flowers solitary or not more than 3 in the cluster (14). 



14. Flowers solitary and subsessile in the axils of small bracts, 

 disposed in racemes or panicles; lower pair of stamens 

 attached near the middle of the corolla tube, the latter 



distended above 12. Dracocephalum. 



14. Flowers solitary or in pedunculate cymules of 2 or 3, in the 



axils of the upper leaves; calyx teeth equaling the calyx 



tube or longer; nutlets pitted (15). 



15. Flowers solitary in the axils; leaves pinnatifid, or (at least 



some of them) 3-lobed; upper lip of the corolla much 



shorter than the lower, which is spreading and obvious. 



1. Teucrium. 



15. Flowers usually in small cymules, sometimes solitary; 



leaves entire or somewhat toothed, not at all lobed; 



limb of the corolla bell-shaped, the lobes subequal (16). 



16. Stamens about as long as the corolla, the latter about 



5 mm. long 3. Is anthus. 



16. Stamens clearly surpassing the corolla, the latter 10 to 

 15 mm. long (17). 

 17. Stamens straight; hairs of the calyx curled downward. 



2. Tetraclea. 

 17. Stamens arched and curving; hairs of the calyx curled 



upward 4. Trichostema. 



13. Flowers several or many at each node, forming an interrupted 

 or congested spike, rarely a terminal head; corolla tube 

 short or, if elongate, then narrow and gradually enlarged 

 upward (except in genus Clinopodium) ; stamens attached 

 near the throat of the corolla (18). 

 18. Anther sacs parallel or nearly so (19). 



19. Leaves 3-parted, the divisions incised 13. Leonurus. 



19. Leaves crenate, serrate, or entire (20). 

 20. Leaves (at least the lower ones) deltoid-ovate, truncate 

 or cordate at base; upper lip of the corolla galeate. 



8. Agastache. 



