LAB1ATVE. (MINT FAMILY.) 347 



* Calyx scarcely at a(l 2-iipped, the teeth and bracts awl-shaped and awn-pointed i 



rigid, naked, as lung as the corol-a : flowers in rather dense mostly terminal heads : 

 leaves rigid, slightly peboled. 



1. P. aristatlim, Michx. Minutely hoary-puberulent (l°-2° high) ; 

 leaves ovate-oblong and oblong-lanceolate, acute, sparingly denticulate-serrate 

 (i'-2' long), roundish at the base. — Pine barrens, from New Jersey southward. 



Var. hyssopifolium, Gray. Leaves narrowly oblong or broadly linear, 

 nearly entire and obtuse. (P. hyssopifolium, Benth.) — Virginia and southward. 



* * Calyx 2-lipped from the greater union more or less of the 3 upper teeth, which), 



with the bracts, are subulate and bearded with some spreading hairs : flowers in 

 dense and compound flattened cymes, which become considerably expanded in fruit.' 

 leaves membranaceous, petioled. (Species 2-5 incline to run together.) 



2. P. 1'ullia, Benth. Leaves greener and loosely soft-downy, only the floral 

 ones whiteneci, 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. — Dry ground, mountains of Virginia and 

 soutbward. 



3. P. incanum, Michx. Leaves ovate-oblong, acute, remotely toothed, 

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

 both sides; cymes open ,• bracts linear-awl-shapcd and, with the calyx-teeth, more 

 or less awn-pointed. — Rocky woods and hills, New England to Michigan, and 

 southward. — Plant 2° -4° high, the taste intermediate between that of Penny- 

 royal and Spearmint, as in most of the following species. Very variable. 



4. P. clinopodioid.es, Torr. & Gr. Leaves oblong-lanceolate, scarcely 

 toothed, short-petioled, not whitened; the upper surface often smooth, the lower 

 as well as the stem downy; cymes contracted ; bracts and calyx-teeth short-subu- 

 late, the latter nearly one half shorter than the tube. — *Dry copses, S. New York 

 to Pennsylvania. Connects No. 3 with No. 5. 



* * * Calyx usually almost equally 5-toothed : flowers crowded in loose heads or dense 



clusters at the end of the branches and in the uppermost axils; the bracts shorter 

 than the 2-lipped corollas : leaves almost sessile. 



5. P. Torreyi, Benth Somewhat pubescent ; 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; the awl-shaped calyx-teeth and bracts 

 canescent. — Dry soil, S. New York to Pennsylvania. — Intermediate in aspect 

 between No. 4 and No. 8. 



6. P. pilbsum, Nutt. More or less downy with long and soft whitish hairs, 

 much branched above ; leaves lanceolate, acute at both ends, or the lower ovate-Ian- 

 ceo'ate, nearly entire, the floral not whitened; calyx-teeth ovate-lanceolate, acute, 

 and with the bracts hoary-hairy. — Dry hills and plains, W. Pennsylvania to 

 Illinois, and southward. 



7. 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 the base, mostly sessile and minutely sharp-toothed, prominently veined, green 

 when old ; the floral ones, bracts, and triangular or ovate calyx-teeth, hoary with a 



