548 LABIATE MENTHA 



LYCOPUS 



at the apex, sharply dentate, mostly rounded at base, usually slender-peti- 

 oled, 1-3 inches loug: spikes dense, becoming 3-8 inches long in fruit: 

 bracts lanceolate-subulate or the lower sometimes larger: calyx villous- 

 pubescent, its 3 upper teeth acute or acutish : corolla 4-6 lines long. In 

 moist soil, eastern Washington to California, Pennsylvania and Ontario. 



II Ovary deeply 4-parted. Nutlets smooth or granulate, with 

 small basal scar of attachment. Seeds mostly exalbumenous. 



Tribe 2 Menthoideae Benth in DC. Prodr. xii, 149. Corolla 

 less strongly bilabiate and the lobes flatter than in the succeeding 

 tribes, upper lip not galeate or concave. Stamens not declined, the 

 posterior pair shorter or wanting. Anthers, in our genera, 2-celled; 

 the cells distinct or more or less confluent. 



3 MENTHA JL. Sp. 576 



Erect or diffuse herbs with simple mostly punctate leaves and 

 small pink, purple or white flowers in axillary whorls, or dense 

 or interrupted terminal spikes. Calyx campanulate to tubular, 

 10-nerved, regular to slightly bilabiate, 5-toothed. Corolla with 

 tube shorter than the calyx, and somewhat irregular 4-cleft limb; 

 the posterior lobe usually somewhat broader than the others, en- 

 tire or emarginate. Stamens 4, equal, erect, sometimes imperfect: 

 filaments glabrous: anthers two-celled, the cells parallel. Ovary 

 4-parted : style cleft at the summit. Nutlets ovoid, smooth. 



M. Canadensis L. Sp. 577. More or less pubescent perennial : stems 

 erect, simple or branched, usually slender, 6-30 inches high : leaves oblong 

 or ovate-oblong- or oblong-lanceolate, slender-petioled acute at the apex, 

 or the lower obtuse, sharply serrate, narrowed to a somewhat cuneate 

 acute or obtuse base, glabrous or very sparingly pubescent, the larger 2-3 

 inches long: flowers all in short and dense sessile axillary glomerules : calyx 

 oblong-campanulate, densely or sparingly pubescent all over, its teeth 

 about one third as long as the tube. In moist meadows, Brit. Columbia 

 to California and across the Continent. 



4 LYCOPUS L. Sp. 21 , 



Perennial herbs with erect or diffuse stems, mostly dentate 

 leaves and small flowers bracted and verticillate in dense axil- 

 lary clusters. Calyx campanulate, regular or nearly so, 4-5- 

 toothed, not bearded in the throat. Corolla campanulate to cy- 

 lindric, equalling or longer than the calyx, the limb nearly equal- 

 ly 4-cleft, or one of the lobes larger and emarginate. Perfect 

 stamens 2, anterior, the posterior pair rudimentary or wanting ; 

 anther-cells parallel. Nutlets smooth, trigonous, truncate at the 

 summit. 



L. Virginicus L. Sp. 21. Glabrous or puberulent: stems slender, 

 6-24 inches high, simple or branched: propagating by long filiform some- 

 times tuber-bearing stolons: leaves lanceolate to ovate-lanceolate, acumin- 

 ate at the apex, coarsely and sharply dentate, narrowed or cuneate at the 

 base, 1-3 inches long, 6-18 lines wide, petioled, or the upper sessile : bracts 

 short, oblong: calyx about a line long, 4- or sometimes 5-toothed, the teeth 

 ovate or ovate-lanceolate, obtuse or subacute: corolla about a line broad, 

 nearly twice as long as the calyx : nutlets as long or longer than the calyx. 



