ORDER XCI. LABIATE. 173 



base. Leaves pubescent, broadly cordate, crcnate, the upper ones ses- 

 sile, clasping, the lower ones on short petioles. Flowers on axillary 

 whorl's. Calyx hairy. Corolla with the tube long, marked with pale 

 spots. — Bright purple. 0. Common. 6 — 8 inches. 



Genus XXV.— ISANTHUS. Mich. 13—1. 

 (From isos, equal, and anthos, flower, the corolla being nearly regular.) 



Calyx campanulate, 10-nerved, 5-toothed ; throat naked. 

 Corolla short, campanulate, of 5 nearly equal rounded lobes. 

 Stamens 4, nearly equal, erect. 



1. I. cceru'i.eus, (Mich.) Viscidly pubescent. Leaves broad-lanceolate, 

 3 nerved. Flowers 1 — 3, on axillary peduncles. — Pale blue. July — 

 Aug. River banks. False Pennyroyal. 



Genus XXVI— TRICHOSTE'MA. L. 13—1. 

 (From tlirix, a hair, and sterna, a stamen.) 



Calyx campanulate, oblique, resupinate, unequally 5-cleft, 

 the 3 upper teeth elongated. Corolla with a slender tube, up- 

 per lip falcate. Stamens 4, long and curved. 



1. T. dicbot'oma, (L.) Stem erect, branching. Leaves ovate-lanceo- 

 late, broad, pubescent, entire. Flowers in dichotomous panicles, solitary, 

 in the divisions of the branches. Calyx hispid, ribbed, bilabiate. Sta- 

 mens unequal. Stigmas 2. — Blue. 0. July — Sept. Dry soils. Very 

 common. 2 — 3 feet. 



2. T. linearis, ("Walt.) Stem viscidly pubescent. Leaves linear, 

 smooth, sessile, acute at each end; teeth of the calyx awned. Stamens 

 very long. — Blue. %. June — Sept. Dry fields. 6 — 12 inches. 



Genus XXVIL— TEU'CRIUM. L. 13—1. 

 (Named after Teucer, son of Scamander.) 



Calyx tubular, or campanulate, nearly equally 5-toothed. 

 Corolla with the tube short, 4 upper lobes of the limb nearly 

 equal, the lowest lobe longest. 



1. T. Canaden'se, (L.) Stem erect, furrowed, pubescent, somewhat 

 jointed. Leaves opposite, ovate-lanceolate, serrate, on short petioles, 



- r torn entose beneath. Flowers in whorled racemes. Bracts subu- 

 late, longer than the calyx Calyx pubescent, with the 3 upper seg- 

 id, the 2 lower narrow. Corolla pubescent, the upper lips 



. . divided. Stigmas 2. — Blue or reddish. If. July — September. 

 Damp soils. Common. 2 — 3 feet. 



2. T. Virgin 'icum, (L.) Stem pubescent, furrowed. Leaves ovate- 

 obloog; serrate ; those near the summit nearly sessile. Flowers in vet- 

 ticillate racemes, crowded. Bracts as long as the calyx. — Blue or pur- 

 ple. H. July — Aug. In wet grounds. 2 — 3 feet. 



