MINT FAMILY 659 



2. Lycopus americanus Muhl. Cut-leaved Water-hoarhound. Fig. 4454. 



Lycopus americanus Muhl. ex Bart. Fl. Phil. Prodr. IS. 1815. 

 Lycopus stnuatus Ell. Bot. S.C. & Ga. 1: 26. 1817. 

 Lycopus europaeus var. sinuatus A. Gray, Man. ed. 5. 346. 1867. 

 Lycopus tacerus Greene, Pittonia 3: 339. 1898. 



Glabrous or sparingly pubescent perennial with rather stout stolons ; stems erect, simple or 

 branched, 3-9 dm. high. Leaves narrowly lanceolate to ovate-lanceolate, 3-10 cm. long, irregu- 

 larly incised or laciniate-pinnatifid, acuminate at apex, tapering at base to a slender petiole ; calyx- 

 teeth triangular-lanceolate, cuspidate ; rudimentary stamens slender, thickened at the tips ; nutlets 

 shorter than the calyx. 



Wet places, Transition and Upper Sonoran Zones; British Columbia southward through the Pacific States 

 to southern California and eastward across the continent. Type locality: Pennsylvania. July-Oct. 



3. Lycopus lucidus Turcz. Pacific Water-hoarhound. Fig. 4455. 



Lycopus lucidus Turcz. ex Benth. in A. DC. Prod. 12: 178. 1848. 

 Lycopus maritimus Greene, Pittonia 3: 340. 1898. 



Pubescent on the stems and midveins of the leaves, rarely nearly glabrous ; perennial with 

 stolons ; rootstock not tuberous or sometimes thickened at the end ; stems usually stout, 3-8 dm. 

 high, erect and strict, simple or rarely branched above. Leaves lanceolate or oblong-lanceolate, 

 4-8 cm. long, 1-2 cm. wide, acute or acuminate at apex, narrowed, sometimes rather abruptly so, 

 to the subsessile base, sharply and evenly serrate ; calyx-lobes lanceolate-subulate, acuminate, 

 longer than the tube, hispidulous on the margins ; corolla but little longer than the calyx ; rudi- 

 mentary stamens slender, somewhat thickened at the tips ; nutlets much shorter than the calyx. 



Wet places, Transition and Upper Sonora Zones; Okanogan County, Washington, southward on both sides 

 of the Cascade Mountains to Lake County, Oregon, and to Shasta and Solano Counties, California; also in 

 eastern Asia. Type locality: In Ircutia, Siberia. June-Oct. 



Lycopus lucidus var. americanus A. Gray, Proc. Amer. Acad. 8: 286. 1870. (Lycopus asper Greene, 

 Pittonia 3: 339. 1898.) Very similar to the typical species, but calyx-lobes triangular-subulate and barely 

 equaling the tube; leaves mostly narrower and abruptly sessile. The variety ranges from Utah to Michigan and 

 Kansas. Some forms in the Pacific States closely resemble it. Type locality: "Saskatchewan." 



Thymus Serpyllum L. Sp. PI. 590. 1753. Creeping Thyme. Stems procumbent or prostrate, woody be- 

 low, 2-4 dm. long, puberulent; leaves 4—7 mm. long, broadly to narrowly ovate, glandular-punctate, short- 

 petioled; flowers in crowded leafy-bracted whorls; calyx 3-4 mm. long, bilabiate; corolla light purple, about 

 S mm. long. Sparingly established along roadsides in western Oregon. Naturalized from Europe. 



26. MENTHA [Tourn.] L. Sp. PI. 576. 1753. 



Odorous perennial herbs with erect or diffuse stems, sessile or petioled usually punc- 

 tate leaves, and small whorled flowers, the whorls axillary or in terminal congested or 

 interrupted spikes. Calyx campanulate to cylindric, 10-nerved, regular or slightly bilabiate, 

 5-toothed. Corolla bilabiate, the tube shorter than the calyx, upper lip entire or emargin- 

 ate, the lower 3-lobed. Stamens 4, equal, erect, included or exserted ; filaments glabrous ; 

 anther-sacs parallel. Ovary 4-parted ; style 2-cleft at the summit. Nutlets ovoid, smooth. 

 [Name from the nymph Minthe, used by Theophrastus.] 



A genus of about 30 species, natives of the north temperature regions. Type species, Mentha spicata L. 



Flower-whorls forming terminal spikes, or some of the lower in the leaf-axils and somewhat distant. 

 Plants glabrous or nearly so. 



Leaves sessile or nearly sessile; spike slender, more or less interrupted. 1. M. spicata. 

 Leaves all distinctly petioled; spikes thick and mostly dense. 



Calyx-lobes ciliate; leaves lanceolate to oblong, acute. 2. M. piperita. 



Calyx-lobes not ciliate; leaves broadly ovate to suborbicular, at least the lower obtuse. 



3. M. citrata. 

 Plants tomentose or villous-tomentose. 



Inflorescence hispidulous but not canescent; calyx hispidulous, its teeth not ciliate; leaves shallowly 

 crenate-serrate. 4. M. rotundifolia. 



Inflorescence canescent; calyx-teeth hispid-ciliate; leaves rather sharply and conspicuously serrate. 



5. M. alopecuroides. 



Flower-whorls all distant and in leaf-axils^ leaves exceeding the whorls, or those of the upper whorls often re- 

 duced and shorter than the whorls m M. Pulegium. 



Leaves rounded or obtuse at apex, those subtending the upper flower-whorls shorter than the whorls and 



turned downward. 6. M. Pulegium. 



Leaves acute at the apex, those of the upper flower-whorls exceeding the whorls and not turned downward. 



7. M. arvensis. 



\. Mentha spicata L. Spearmint. Fig. 4456. 



Mentha spicata L. Sp. PI. 576. 1753. 

 Mentha viridis L. Sp. PI. ed. 2. 804. 1763. 



Perennial with stolons, glabrous or sparingly pubescent at the nodes ; stems 3-12 dm. high, 

 often purplish. Leaves oblong-lanceolate to ovate-lanceolate, sessile or short-petioled, sharply 

 serrate, acute or acuminate at the apex, obtuse, somewhat rounded or subcordate at base, the 

 larger 3-6 cm. long ; flower-whorls in slender terminal leafless spikes often 6-8 cm. long in fruit ; 

 bracts subulate-lanceolate, equaling or surpassing the calyx, ciliate; calyx-teeth subulate, about 



