410 LABI AT M. (MINT FAMILY.) 



3. P. Iinif61ium, Pursh. Smoother and leaves narrower and heads less 

 downy than in the last; the narrower bracts and lance-awl-shaped calyx-teeth 

 pungently pointed. Dry ground, Mass, to Minn., south to Ma. and Tex. 



*- - Leaves lanceolate to ovate, sessile or nearly so, denticulate or entire ; head* 

 larger and fewer, with fewer and looser bracts. 



4. P. muticum, Pers. Minutely hoary throughout, or becoming almost 

 smooth, corymbosely much branched (1-2| high); leaves ovate or broadly 

 ovate-lanceolate, varying to lanceolate, rather rigid, acute, rounded or slightly 

 heart-shaped at base, mostly sessile and minutely sharp-toothed, prominently 

 veined, green when old ; the floral ones, short bracts, and triangular or ovate 

 calyx-teeth, hoary with a fine close down ; flower-clusters very dense. Maine 

 to S. 111., south to Fla. and Ark. 



Var. pildsum, Gray. Hoary with loose pubescence ; leaves thinner, oblong- 

 lanceolate, mostly acute or acutish at base ; bracts and especially the narrower 

 (often somewhat unequal) calyx-teeth often villous-pubescent. (P. pilosum, 

 Nutt.) Ohio to Iowa, Kan., and Ark. 



5. P. leptodon, Gray. Soft-pubescent, or glabrate below, loosely branched ; 

 leaves membranaceous, green (1^-2' long), lanceolate or oblong -lanceolate, sub- 

 sessile ; clusters larger and looser, canescent-hirsute ; long -acuminate bracts and 

 calyx-teeth slender-subulate, villous-hirsute. S. Mo. to northwestern N. C. 

 *-*-- Leaves linear- or oblong -lanceolate, short-petioled, not at all hoary ; flow- 

 ers in mostly terminal dense capitate clusters ; calyx hoary-pubescent. 



6. P. Torrdyi, Benth. Puberulent; stem strict and nearly simple ( 2 - 

 3 high) ; leaves thin, linear-lanceolate, tapering to both ends (mostly 2' long 

 and 2 - 3" wide), nearly entire ; heads small ; awl-shaped calyx-teeth and mostly 

 appressed bracts canesceut. Dry soil, southern N. Y. to Penn. and Del. 



7. P. clinopodioid.es, Gray. Pubescent; leaves broadli/ or oblong -lan- 

 ceolate, sharply denticulate (sometimes entire) ; heads fewer and larger; bracts 

 loose. Dry soil, southern N. Y. to E. Penn. 



* * * Calyx bilabiate (3 upper teeth united], the teeth and the tips of the loose 



bracts not rigid ; flowers in dense flattened glomerate cymes; leaves thin, 

 mostly serrate, petioled, the uppermost more or less canescent. 



8. P. Ttillia, Benth. Leaves greener and loosely soft-down //, only the 

 floral ones whitened, otherwise resembling those of the next ; cymes dense ; 

 bracts much surpassing the flowers, their long awn-like points and the awn- 

 pointed calyx-teeth bearded with long loose hairs. S. Va. and N. C. to Tenn. 

 and Ga. 



9. P. inc&num, Michx. Leaves ovate-oblong, acute, remotely toothed. 

 downy above and mostly hoary with whitish wool underneath, the uppermost whit- 

 ened both sides ; cymes open ; bracts linear-awl-shaped and, with the calyx-teeth, 

 more or less awn-pointed. N. Eng. to Ont. and Ind., south to Fla. and Tex. 



* * * * Calyx equally 5-toothed ; heads few t large and globose (terminal and 



in the upper axils of the thin petioled leaves) ; bracts loose, ciliate-bearded. 



10. P. mont&num, Michx. Stem (1-3 high) and ovate- or oblong- 

 lanceolate serrate leaves glabrous ; bracts very acute or awl-pointed, the outer- 

 most ovate and leaf-like, the inner linear ; teeth of the tubular calyx short and 

 acu te. Alleghanies, from S. Va. and Tenn. to Ga. and Ala. 



