CLASS XIV. ORDER I. 249 



the lips closed ; rudiment of a fifth glabrous, filament 

 between the upper stamens. 



DIDYNAMIA. 

 G YMNOSPBRMIA. 



253. GLECHOMA. 



Glechoma hederacea. Zr. Ground Ivy. Gill. 



Leaves reniform, crenate. 



A creeping plant, usually fonnd about fences or in shady 

 places. Sten:is square, procumbent. Leaves opposite, petioled, 

 heart or kidney shaped, crenate, hairy. Flowers in whorls, a 

 few together. Calyx striated, ending in five unequal, pointed 

 segments. Corolla blue, the upper lip straight, the lower ex- 

 panded, three lobed, the middle lobe emarginate. Each pair of 

 anthers meet, forming a cross. Ground ivy has a peculiar 

 strong taste and smell, and possesses some medicinal reputa- 

 tion. — May, Juue. — Perennial. 



254. MENTHA. 

 Mentha borealis. Mich. Horscmint. 



Ascending, low, pubescent ; leaves petioled, oval- 

 lanceolate, acute at both ends; tlowers in whorls, 

 stamens projecting. Mich. 



Inhabits the banks of rivulets and ditches. Stem square, hairy 

 backwards. Leaves opposite, on downy petioles, oval, acute, 

 serrate, the upper ones lanceolate. Flowers in regular, axillary 

 whorls, on short peduncles. Corolla pale purple. Stamens 

 twice as long as the corolla. — June, July. — Perennial. The 

 taste and properties resemble those of Pennyroyal. 



Mentha viridis. L. Spearmint. 



Spikes interrupted; leaves sessile, lanceolate, acute, 

 naked ; bractes setaceous, and, with the calyx teeth, 

 somewhat hairy. Sm. 



