416 POWDERED VEGETABLE DRUGS 



138. (Fig. 137.) MENTHA PIPERITA. Peppermint. U. S. 



P^efferminze, G. Mentha poivre*e, Fr. 



The leafy tops of Mentha piperita L., Labiatse. 



Green. 



Aromatic, somewhat fragrant. Mint odor. 



Pungent; very cooling. 



Leaves with stomata above and below, few above; vertical walls 

 thin, wavy. Large, long, rather thick-walled, three to seven celled 

 simple trichomes with short linear to warty cuticular thickenings. 

 Large bladdery glandular trichomes with six to eight secreting cells. 

 Small secreting trichomes with a single terminal secreting cell. Be- 

 sides this there is present stem tissue, as epidermis, collenchyma, paren- 

 chyma, tracheids and ducts. 



Ash 12.5 per cent. 



Adulterated with leaves of several varieties of M. piperita and 

 with spearmint. 



139. MENTHA VIRIDIS. Spearmint. U. S. 

 Coarse powder. 



Griine Minze, Romische Minze, G. Menthe vert, Mentha romaine, 

 Baume vert, Fr. 



The leafy tops of Mentha viridis L., Labiatse. 



Green. 



Very fragrantly aromatic. 



Pungent, less cooling than M. piperita. 



Vertical walls of upper and lower epidermal cells of leaves wavy. 

 Upper epidermal cells somewhat larger with only comparatively few 

 stomata. Simple trichomes rather thick-walled but fewer and shorter 

 than in peppermint; cuticular markings less prominent and less 

 decidedly linear, more warty. Glandular trichomes are similar to 

 those of peppermint. 



Ash 12.5 per cent. 



According to several authorities the glandular trichomes of pepper- 

 mint are distinguished at once by the menthol crystals, a characteristic 

 which does not seem to be marked. May be admixed and adulterated 

 with various species and varieties of mint. 



