710 LABIATAE (MINT FAMILY) 



* * Leaves incised or pinnatifid at least at base. 



6. L. EUROPAEUS L. Rarely stoloniferous, not tuberiferous ; stem coarse, 

 mure or less villous, 1 m. or less high ; leaves petioled, ovate, pubescent, coarsely 

 toothed, sinuate or pinnatifid at base; calyx-teeth subulate-tipped. Damp or 

 waste ground, Mass to Va. (Nat. from Eu.) 



7. L. americanus Muhl. Stem erect, slender, 2-9 dm. high, acutely 4-angled, 

 fjlabrate, freely stoloniferous; leaves oolong or lanceolate, acuminate, irregu- 

 larly incised or laciniate-pinnatiftd, the upper narrow and merely sinuate, all 

 tapering to slender petioles ; calyx-teeth short-cuspidate ; sterile filaments slen- 

 der, conspicuous, with globular or spatulate tips. (L. sinuatus Ell.) Damp 

 soil, Nfd. to B. C., and southw. 



32. MENTHA [Tourn.] L. Mnrr 



Calyx bell-shaped or tubular, the 6 teeth equal or nearly so. Corolla with a 

 short included tube, the upper lobe slightly broader, entire or notched. Stamens 

 4, equal, erect, distant. Odorous perennial herbs ; the small flowers mostly in 

 close clusters, forming axillary capitate whorls, sometimes approximated in in- 

 terrupted spikes, produced in summer, of two sorts as to the fertility of the sta- 

 mens in most species. Corolla pale purple or whitish. Species mostly adventive 

 or naturalized from Europe, with many hybrids. (M.lv6i) of Theophrastus, from 

 a Nymph of that name, fabled to have been changed into Mint by Proserpine.) 



* Spikes narrow and leafless, densely crowded ; leaves sessile or nearly so. 

 t- Spikes canescent. 



1. M. LONGIFOLIA (L.) Huds. (HORSE M. of Eu.) Finely pubescent or ca- 

 nescent; leaves ovate-oblong to oblong-lanceolate, acute, sharply serrate, often 

 glabrous above ; spikes rather slender, canescently pubescent. (Jtf. sylvestris L.) 

 Roadsides, etc., Ct. to Del., Pa., and 0. (Nat. from Eu.) 



2. M. ALOPECimoiDES Hull. Downy ; leaves larger, more nearly sessile, 

 broadly oval and obtuse, often subcordate, coarsely open-dentate, more veiny, 

 but not rugose above ; spikes coarser, canescent ; approaching the next. Damp 

 roadsides, etc., Ct. to N. J., Mo., and Wise. (Nat. from Eu.) 



- - Spikes not canescent. 



3. M. ROTUNDIFOLIA (L.) Huds. Soft-hairy or downy ; leaves broadly ellip- 

 tical to round-ovate and somewhat heart-shaped, rugose, coarsely crenate-toothed ; 

 spikes slender. At a few stations, Me. to O., Fla., and Tex. (Nat. from Eu.) 



4. M. SPIC\TA L. (SPEARMINT.) Nearly smooth ; leaves oblong- or ovate- 

 lanceolate, unequally serrate, sometimes short-petioled ; bracts linear-lanceolate 

 and subulate, conspicuous. (M. viridis L.) Wet places, common. (Nat. 

 from Eu.) 



* * Flowers pedicellate, less crowded in interrupted leafless spicifonn clusters or 

 terminal heads, or some in the upper axils ; leaves petioled. 



*- Calyx (at least the teeth) more or less hirsute. 



6. M. PIPER!TA L. (PEPPERMINT.) Glabrous, very pungent-tasted ; leaves 

 ovate-oblong to oblong-lanceolate, acute, sharply serrate ; spikes becoming loose ; 

 calyx glabrous below, the teeth hirsute. Along brooks, frequent. (Nat. 

 from Eu.) 



6. M. AQUATICA L. (WATER M.) Pubescent with recurved hairs; leaves 

 ovate or round-ovate ; flowers in a terminal globular or intei-rupted and ellipsoid 

 head, often with one or more clusters in the axils of the upper leaves ; calyx and 

 pedicels hairy. Wet places, N. S. to Del., rare. (Nat. from Eu.) 



7. M. CRfspA L. Glabrous or slightly pubescent ; leaves short-petioled, ovate 

 to orbicular, lacerate-dentate and crisped; spikes narrow ; calyx slightly pubes- 

 cent or glabrate below. Wet ditches, etc., Ct. to Pa. (Nat. from Eu.) 



