38 DIDYNAMIA. GTMNOSPERMIA. 



tensely bitter; flowers very conspicuous and of a fine 

 blue, palate of the lower lip marked with a divided con- 

 fluent yellow blotch. 9.pilosa. 10. serraia. Leaves ob- 

 long-ovate, crenate, smooth beneath. 



11. • canesccns. Tall and branching-; leaves ovate, 

 acute, acutely toothed and petiolate, under side with the 

 bractes arid flowers closely and canescently villous, low- 

 er leaves subcordate; racemes pedicellate, subpaniculate, 

 axillary and terminal; bractes ovate lanceolate, longer 

 than the calix. Hab. In the plains and open forests of 

 Ohio. S incann? Muhlenberg's Catal. Obs. Peren- 

 nial. Stems 2 or 3 feet high, canescent. Leaves conspi- 

 cuously petiolate, truncate or subcordate at the base, 

 V hitish beneath, opaque. Racemes partly lateral and ter- 

 minal, elegantly villous and canescent, pubescence very 

 short. Flowers deep blue and of considerable size. 

 Somewhat allied to *S'. serrata but distinct and a much 

 finer species. 



12- * xey-sicolor. Robust and branching; the whole plant 

 except the leaves covered with a soft and glandular pubes- 

 cence; leaves broad-cordate, large, and (;btusely toothed, 

 nearly smooth; petioles very long; racemes ternate, ter- 

 minal, bractes ovate; flowers smallish, particolored. 

 Hab. With the above. Obs. The largest North Ameri- 

 can species, and very distinct. Root perennial. Stem 3 

 or 4 feet high. Leaves thin and diaphanous, a little hir- 

 sute above, 2 or 3 inches broad and 3 or 4 long, destitute 

 of bitterness; peduncles 1 -and a half to 2 inches long. 

 Racemes partly secund, 6 to 8 inches in length; bractes 

 broad-ovate, short and sessile, viscidly pubescent beneath 

 as well as the rachis and calix. Corolla rather small, up- 

 per lip blue, the lower white, S. cordifoliaP Muhl. Catal. 



A considerable genus, of which there are 6 species in 

 Europe, 2 in Siberia, 4 in the Levant, 1 in China, a shrub- 

 by species in Persia^ 2 in tropical America, and 1 in Para- 

 guay. 



4ir. THYMUS. L. (Thyme.) 



Calix subcampanulatc, orifice closed wi h vil- 

 lous hairs. Upper lip of the corolla flat, cinar- 

 ginate. 



Low herbaceous, and pungently aromatic plants; leaves 

 small; flowers conglomerate axillary and often terminal. 



Species. 1. T. Seipijllum. Naturalized in some locali' 

 ties in Pennsylvania. 



