95 

 LABIATAE, the Mint Family 



Herbs with opposite leaves, square stems, and usually aromatic 

 odor; flowers irregular, with united petals, or almost regular; stamens 

 2 or 4, attached to the tube of the corolla; ovary deeply 4-lobed, with 

 a single style. 



la. Stamens 2 2. 

 Ib. Stamens 4 15. 



2a. Corolla regular or nearly so; flowers white, in dense axillary 

 clusters; plants usually of wet grounds (2 8 dm. high; sum- 

 mer and autumn) 3. 



2b. Corolla distinctly irregular and more or less 2-lipped 7. 



3a. Calyx-teeth short, triangular, acute or obtuse (Bugle Weed) 4. 

 3b. Calyx-teeth narrow, acuminate or cuspidate (Water Hoarhound) 



5. 



4a. Stems and stolons bearing tubers 



Bugle Weed, Lycopus imiflorus. 

 4b. Stems and stolons not bearing tubers 



Bugle Weed, Lycopus virglnicus. 



5a. Leaves serrate; calyx-teeth sharp-pointed 6. 

 5b. Leaves coarsely incised; calyx-teeth awn-tipped 



Water Hoarhound, Lycopus americanus. 



6a. Corolla twice as long as the calyx; leaves narrowed at the 

 base Water Hoarhound, Lycopus rubellus. 



6b. Corolla barely longer than the calyx; leaves sessile or near- 

 ly so Water Hoarhound, Lycopus lucidus var. americanus. 



7a. Corolla blue, 3 4 mm. long; flowers in loose axillary clusters 



(1 4 dm. high; summer) (Pennyroyal) 8. 

 7b. Corolla 840 mm. long 9. 



8a. Leaves serrate Pennyroyal, Hedeoma pulegloides. 



8b. Leaves linear, entire Pennyroyal, Hedeoma hispida. 



9a. Lower lobe of the corolla fringed, very much longer than the 

 upper (5 15 dm. high; corolla pale-yellow; late summer) 



Horse Balm, Colliusonia canadensis. 



9b. Lower lobe of the corolla nearly or quite as long as the upper 

 and not fringed 10. 



lOa. Calyx narrowly tubular; its teeth about equal in size (5 10 

 dm. high; flowers in dense terminal heads, in summer) 11. 



lOb. Calyx campanulate, 2 of its teeth different in size from the 

 other 3 (4 8 dm. high; flowers pink-purple, in terminal clusters 

 in summer) 14. 



