LABIATJE. (MINT FAMILY.) 315 



5. P. muticum, Pers. Smooth or tomcntosc ; stem corymboscly branched ; 

 leaves ovate or ovate-lanceolate, acute, serrate, rounded or slightly cordate at 

 the base, sessile or short-petioled, the uppermost whitened ; cymes small, com- 

 pact, corymbose, minutely hoary-tomentose ; calyx-teeth short, triangular-ovate, 

 obtuse. Dry soil, Florida to Mississippi, and northward. Aug. and Sept. 

 Stem 1 - 2 high. Leaves 1 ' - 2' long. 



*-- Cymes capitate, in compact corymbose clusters : bracts shorter than the 

 flowers : stem and rigid entire leaves smoothish. 



6. P. lanceolatum, Pursh. Stem branched ; leaves lanceolate or linear- 

 lanceolate, acute, rounded at the base ; cynics numerous, pubescent ; bracts 

 ovate-lanceolate ; calyx-teeth short, triangular. Dry soil in the upper districts. 

 Aug. and Sept. Stem 2 high. Leaves l'-2' long. 



7. P. linifolium, Pursh. Stem branched ; leaves very numerous, linear, 

 sessile ; cymes smoothish ; bracts linear, acute ; calyx-teeth lanceolate-subulate, 

 rigid, acute. Dry soil, Florida to Mississippi, and northward. Aug. and Sept. 

 Stem 2 high. 



8. P. nudum, Nutt. Smooth ; stem simple or corymbose at the summit, 

 straight ; leaves sessile, ovate-oblong, obtuse, rounded at the base ; cymes 

 smooth; exterior bracts narrow-lanceolate, the inner short, subulate; calyx- 

 teeth short, triangular-lanceolate, and, like the corolla, pubescent. Low pine 

 barrens, Dale County, Alabama, to the mountains of North Carolina. Aug. 

 and Sept. Stem 2 high. Leaves ' - V long. 



H- - -*- - Cymes axillary and terminal, large, dense-flowered: bracts ciliate. 



9. P. montanum, Michx. Stem slender, smooth, simple or branched; 

 leaves smooth, ovate-lanceolate, serrate, acute, tapering into a short petiole, the 

 lowest rounded at the base ; cymes globose, the upper ones closely sessile ; 

 bracts numerous, ciliate ; the exterior ovate, very acute, as long as the flowers, 

 the inner ones linear ; calyx-teeth short, acute ; ovary bearded. Mountains of 

 North Carolina. July and Aug. Stem 1 - 3 high. Leaves 2' - 3' long. 



7. COLLINSONIA, L. HORSE-BALM. 



Calyx obovate, enlarged and deflexed in fruit, 2-lipped ; the upper lip flat- 

 tened, truncate, 3-toothed, the lower 2-cleft. Corolla funnel-shaped, 2-lipped, 

 dilated at the throat ; the four upper lobes equal, the lowest larger, declining, 

 toothed or fimbriate. Stamens 2 or 4, long-exserted, spreading : anther-cells 

 diverging. Nutlets smooth. Strong-scented perennial herbs. Leaves large, 

 coarsely serrate, dotted beneath. Flowers yellowish, solitary, opposite, in 

 racemes or panicles. Petioles tumid at the base. 



* Fertile stamens 2. 



1. C. Canadensis, L. Nearly smooth; leaves ovate or oblong-ovate, 

 acuminate, sharply serrate, acute, rounded or cordate at the base, long-pctioled, 

 the uppermost smaller, sessile ; panicle elongated ; bracts minute, very acute ; 

 flowering calyx very small, the upper lip much shorter than the lower, with 



