S8 DIDYNAMIA. GYMNOSPERMIA. 



tensely bitter; flowers very conspicuous and of a fine 

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

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

 long-ovate, crenate, smooth beneath. 



11. * canesceJis. Tall and branching-; leaves ovate, 

 acute, acutely toothed and petiolate, under side with the 

 bractes and 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 incana? Muhlenberg's Catul. Obs. Peren- 

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

 cuously petiolate, truncate or subcordate at the base, 

 whitish 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. * versicolor. Robust and branching; the whole plant 

 except the leaves covered with a soft and glandular pubes- 

 cence; leaves broad-cordate, large, and obtusely 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 ilitle 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 therachis and calix. Corolla rather small, up- 

 per lip blue, the lower white, .S". covdifolia? 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. THYMUSo L. (Thyme.) 



Calix subcampanuiate, orifice dosed with vil- 

 lous hc.ii's. Ui)per lip of tliQ corolla flat, emar- 

 ginate. 



Low- herbaceous, and pungently aromatic plants; leaves 

 small; flowers conglomerate axillary and often termmal. 



Species. 1. T.Serpyllum. Naturalized in some locali- 

 ties in Pennsylvania. 



