708 LABIATAE (MINT FAMILY) 



very numerous, obtuse at base ; capitate glomerules small and numerous, densely 

 corymbose, imbricated with many short appressed downy rigid ovate or lanceo- 

 late bracts; calyx-teeth short and triangular. (Koellia MacM. ; P. lanceolatum 

 Pursh.) Dry banks, centr. Me. to Dak., and southw. 



7. P. TorrSi Benth. Puberulent; stem strict and nearly simple, 5-9 dm. 

 high ; leaves thin, lanceolate or linear-lanceolate, tapering to both ends, petioled, 

 nearly entire ; flowers in mostly terminal dense capitate clusters ; awl-shaped 

 calyx-teeth and mostly appressed bracts canescent. (Koellia verticillata Am. 

 auth., in part, not Ktze.) Dry soil, N. Y. and Pa. to Ga. 



b. At least the uppermost leaves closely puberulent above. 



8. P. pilosum Nutt. Hoary with loose pubescence ; leaves thick, pubescent 

 and dull, oblong-lanceolate, entire, mostly acute or acutish at base, the upper 

 green ; bracts and especially the narrow (often somewhat unequal) calyx-teeth 

 villous-pubescent, canescent; stamens exserted. (Koellia Britton ; P. muticum, 

 var. Gray.) Prairies and dry woods, Pa. to la., Kan., and Ark. 



9. P. verticill&tum (Michx.) Pers. Stem closely pubescent, especially 

 above ; leaves lanceolate, entire or subentire, subsessile, mostly glabrous, only 

 the upper closely puberulent and paler ; bracts of the glomerules ovate-lanceo- 

 late, ciliate, with subulate tips; stamens included. {Koellia Ktze.) Moist 

 fields and open woods, w. Que. , Vt. , and e. Mass, to N. C. 



*-* -* Leaves ovate or ovate-oblong. 

 = Calyx and bracts densely invested with close minute appressed pubescence. 



10. P. incanum (L.) Michx. Leaves ovate-oblong, acute, remotely toothed, 

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

 whitened both sides ; cymes large, open, mostly verticillastrate or terminal, few ; 

 bracts linear or lanceolate, more or less bristly-ciliate ; calyx-teeth deltoid, short, 

 herbaceous, rarely a little bristly-ciliate. (Koellia Ktze.) Open woods, Vt. 

 and Mass, to Ont., Mo., and southw. 



11. P. albescens T. & G. Closely resembling the preceding, but with no vil- 

 lous pubescence, the leaves closely cinereous-puberulent beneath. (Koellia Ktze.) 

 Low sandy ground, Va. and Ky. to Fla. and Tex. 



= = Calyx and bracts pilose or hispid with distinct spreading hairs. 



12. P. muticum (Michx.) Pers. Minutely hoai-y throughout, or becoming 

 almost smooth, corymbosely much branched, 3-9 dm. high ; leaves ovate er 

 broadly ovate-lanceolate, rather rigid, acute, rounded or slightly heart-shaped at 

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

 glabrate when old ; the floral ones and the subulate-tipped lance-attenuate or 

 linear bracts and the calyx-teeth hoary ; flower-clusters very dense, corymbose; 

 stamens exserted. (Koellia Britton.) N. H. to Mo., and southw. 



13. P. montanum Michx. Glabrous or essentially so, tall (6-10 dm. high), 

 simple or sparingly branched above; leaves lance-ovate or -oblong, thin, sharply 

 serrate, acuminate ; heads chiefly in the upper axils, or solitary at the tips of the 

 elongate branches; the long thin bracts long-acuminate, ciliate-hispid ; calyx- 

 teeth deltoid-subulate, smoothish. (Koellia Ktze.) Mountain woods, Va. to 

 Tenn., and southw. 



29. THYMUS [Tourn.] L. THTMB 



Calyx 13-nerved, hairy in the throat ; the upper lip 3-toothed, spreading ; the 

 lower 2-cleft, with the awl-shaped divisions ciliate. Corolla short ; the upper 

 lip straight and flattish, notched at the apex, the lower 3-cleft. Stamens 4, 

 straight and distant, usually exserted. Low perennials, with small and entire 

 strongly veined leaves, and purplish or whitish flowers. (The ancient Greek 

 name of the Thyme, probably from (Meiv, to burn perfume, because it was used 

 for incense. ) 



1. T. SERPYLLUM L. (CREEPING T.) Prostrate ; leaves green, flat, ovate, 

 entire, short-petioled ; flowers crowded at the ends of the branches. Old fields, 

 etc., N. S. to N. Y. and Pa, July, Aug. (Nat. from Eu.) 



