314 LABTAT-E. (mINT FAMILY ) 



6. PYCNANTHEMUM, Mlchx. IIorse-mint. 



Calvx tiilmlnr, l.lncrvcd, nnkccl in the throat, equally S-tootlied, or slightly 

 2-li]i))(.d. C'oiolla 2-lipped ; the upper lip notched or entire, the lower 3-elcft. 

 StuHKMis 4, nearly c(inal, straigiit, spreading, commonly exserted : anther-cells 

 parallel. Style 2-cleft at the apex. Nutlets smooth. — Perennial mostly pu- 

 bescent or hoary herbs, with erect branching stems. Floral leaves often white- 

 tomcntose. Cymes mostly terminal, bracted. Corolla small, white or purplish 

 — Plants aromatic and pungent. 



♦ Calyx more or less 2-lippc(l, ike subulate teeth often bearded irlth tirak Jniiitrd hairs : 

 cymes musttij terminal, icidelj spreading in fruit : brads loiujer titan the JJowtrs: 

 leaves jiubi scent, the uppei'most white7ud. 



1. P. incanum, Michx. Stem densely pubescent and hoary; leaves ovate 

 or oblong-ovate, acute, sharply serrate, short-petioled, hoary-iomentose beneath ; 

 calyx-teeth subulate, and, like the bracts, commonly bearded with weak hairs. 

 (P Loomisii, A'^t//^) — Var. TuLLiA. {P. TaW'ni, Benth.) Leaves smaller and 

 smoother ; cymes larger and more expanded ; calyx-teeth longer. — Var. al- 

 bescens. (P. albescens, Gray.) Leaves ovate-lanceolate, obtuse, smooth above, 

 hoary beneath; calyx-teeth triangular lanceolate, obtuse, not bearded. — Dry 

 woods and fence-rows, Florida to Mississippi, and nortlnvard. Aug. and Sept. — 

 Stem 2° -4° high. Leaves l'-2' long. Flowers white. 



2. P. dubium, Gray. Stem vilio'us-pubcscent ; leaves lanceolate, acute 

 at each end, smooth or nearly so, entire; cymes hoary, dense-flowered, short- 

 pedunclcd ; calyx-teeth subulate, tipped, like the bracts, with a tuft of weak 

 hairs; the 2 lower ones shorter. — Mountains of North Carolma. Aug. and 

 Sept. — Stem 2° - 3° high. Leaves 2' - 3' long. 



* * Calyx-teeth nearly equal. 



■*- Calyx as long as the corolla; the teeth subulate and aicn-pointtd , like the rigid 



bracts: cymes dense-Jlou-tnd 



3. P. aristatuna, Michx. Tomentose and hoary, or soniotimcs hairy ; 

 stem branched ; leaves ovate or oblong, acute, sparingly serrate, louiidcd at the 

 base, short-petiolcd, the uppermost somewhat whitened ; cymes uio-itly terminal ; 

 ovary bearded. — Var. iiyssoi'ifolium. Gray. Stem simple or corymbose 

 above; leaves rigid, linear-oblong, obtuse, entire. — Low ground, Florida to 

 Mississippi, and nortlnvard. Aug. and Sept. — Stem l^,°-3° high. Leaves 

 I' -2' long. 



■♦- ••- Calyx-teeth beardless and awnless : cymes capitate, mo<illy terminal .• bracts 

 shorter than the flowers : leaves suhsessile. 



4. P. pilosum, Nutt. Softly pubescent or villous ; branclies short, erect ; 

 leaves laiu-colate, entire, acute at each end, none of them whitened ; cymes 

 small, compact, corymbose ; calyx-teeth ovate-lanceolate, acute, and, like the 

 bractM, hoary-tomcniose, or, in var. i,i;i>toi)ON, Gray, subulate imd villous. — 

 Upper districts of Georgia, and nonliward Aug. and S(']»t. — Stem 2° high. 

 Leaves l'-2' long. 



