FLOWERING PLANTS AND FERNS OF ARIZONA 785 



23. MENTHA. Mint 



Perennial aromatic herbs, usually of wet places, with creeping, 

 mat-forming rhizomes; leaves ovate or oblong, serrate; flowers small 

 and pinkish in dense clusters in the axils of the upper leaves, or in 

 narrow dense terminal spikes; calyx equally 5-toothed, the teeth 

 deltoid, acute, usually shorter than the tube; corolla subequally 

 5-lobed; stamens 4, exserted; nutlets smooth. 



Two Old World species, peppermint {Mentha piperita) and spear- 

 mint (M. spicata), are commonly cultivated. Oil of peppermint is 

 used extensively in medicine and confectionery. Spearmint is used 

 fresh for flavoring juleps, mint sauce, etc., and the oil is extracted, 

 chiefly for medicinal use. The Hopi use mint leaves for flavoring 

 mush. 



Key to the species 



1. Flowers in axillary clusters 1. M. arvensis. 



1. Flowers in terminal spikes 2. M. spicata. 



1. Mentha arvensis L., Sp. PL 577. 1753. 



Mentha penardi (Briq.) Rydb., Torrey Bot. Club Bui. 33: 150. 

 1906. 



Apache, Coconino, Greenlee, and Cochise Counties, probably 

 elsewhere, 5,000 to 9,500 feet, July to October. Species circumpolar, 

 polymorphic. 



2. Mentha spicata L., Sp. PL 576. 1753. 



Prescott, Yavapai County (Peebles et al. 2684), Tonto Basin, 

 Gila County (Tourney 302). Extensively distributed in North 

 America; naturalized from Europe. 



M. rotundifolia L., a species closely related to M. spicata but distinguished by 

 more obtuse and hairy leaves, is to be looked for in Arizona. 



24. HYPTIS 



A shrub, usually canescent, the hairs branched; leaves ovate; 

 flowers several in axillary or subspicate globose woolly cymules, 

 these sometimes paniculate; calyx usually 10-veined, the tube cylin- 

 dric, enlarging somewhat at maturity, the teeth subequal, subulate; 

 corolla violet, the tube little exserted from the calyx, the upper lip 

 plane or laterally reflexed, the middle lobe of the lower lip deeply 

 saccate; stamens 4, declined along the lower lip, paired; nutlets 

 smooth, oblong. 



1. Hyptis emoryi Torr. in Ives, Colo. River Rpt. 20. 1860. 



Hyptis lanata Torr., U. S. and Mex. Bound. Bot. 129. 1859. 

 Not Pohl. 



Mohave, Yavapai, Graham, Maricopa, Pinal, Pima, and Yuma 

 Counties, up to 5,000 feet (usually lower), dry rocky slopes and 

 canyons, flowering almost throughout the year at lower elevations, 

 type from the lower Gila River (Emory). Southern Arizona , southern 

 California, and northwestern Mexico. 



Desert-lavender. The plant is browsed to a limited extent by 

 livestock. The seeds, like those of certain species of Salvia, are 

 used in Mexico as food under the name "chia." 



