LABIATE. 281 



Barren fields and woods. Arct. Amer. to N. Y. W. to Miss. May Aug. (g). 

 Nearly smooth. Stem 8 15 inches high, obtusely 4-angled. Flowers pale-blue, 

 in ovoid or globose spikes which are about an inch in diameter. 



Small-flowered Dragon's Head. 



VII. STACHTDE-E. Calyx 5 10-nerved or irregularly veined. Co- 

 rolla 2-lipped. Stamens 4, ascending ; the lower pair longer. Achenia 

 smoothish when dry. 



20. PHYSOSTEGIA. Denth. Physostegia. 



(From the Greek uja, a bladder, and orfy*?, a covering ; in allusion to its 

 Inflated calyx.) 



Calyx 5 -toothed or truncate, at length inflated-campanulate. 

 Corolla 2-lipped ; tube exserted, destitute of a ring within ; up- 

 per lip nearly erect, somewhat concave ; lower with 3 rounded 

 lobes, the middle one larger and emarginate. Stamens 4, 

 ascending under the upper lip ; the lower pair rather longer. 



P. Virginiana Benth. : calyx acutely and almost equally 5-toothed. 

 Dracocephalum Virginianum Linn, and D. denticulatum Ait, D. vari- 

 egatum Vent. 



Low grounds. Can. to Flor. W. to Miss. June Aug. % Stem about 

 2 feet high, smooth except at the summit. Leaves sessile, opposite, varying from 

 narrow-lanceolate to ovate-lanceolate, acutely serrate or denticulate, coriaceous. 

 Flowers large, pale-purple, sometimes variegated, nearly sessile and usually 

 opposite, in long spikes, crowded or somewhat distant. I follow Bentham in 

 uniting the two or three species heretofore considered distinct, but not without 

 considerable hesitation. I cannot help thinking, with Dr. Darlington, that 

 D. denticulatum of previous authors will eventually prove to be, if not a distinct 

 species, at least a constant variety. Dragon's Head. 



21. LAMIUM. Linn. Dead Nettle. 

 (From the Greek Xat/*c?, the throat; on account of the shape of the flower.) 



Calyx tubular-campanulate, about 5-nerved, with 5 nearly 

 equal subulate teeth. Corolla 2-lipped ; upper lip oblong or 

 ovate, galeate ; throat dilated; lower lip with the middle or 

 lower lobe broad, emarginate, contracted at base. Stamens 4, 

 the lower pair longer. 



L. amplcxicaide Linn. : leaves rounded, crenately incised ; lower ones 

 petiolate ; floral sessile, clasping ; tube of the corolla naked within. 



Fields and road-sides. N. S. May Nov. (T).Stcm 610 inches high, 

 branched from the base. Flowers with the tube slender, purple^ in dense whorls. 

 Introduced from Europe. Common Dead Nettle. Hen-bit. 



22. LEONURUS. Linn. Motherwort. 



(From the Greek Xtwr, a lion, and ovoa, a tail ; on account of a fancied 

 resemblance in the plant.) 



Calyx turbinate, 5-nerved, with 5 subulate equal teeth. 

 Corolla 2-lipped ; upper lip very hairy above, entire ; lowe. 



