312 LABIATAE. 



stamens 4, short, included in the corolla-tube, the upper pair 

 longer. 



Marrubium vulgare L. Horehound. Stems tufted, erect, simple, about 

 30 cm. high, densely white woolly, especially below; leaves broadly ovate, 

 obtuse, coarsely crenate, thickish, rounded or cuneate at base, rough, woolly 

 beneath, 1-3 cm. long, on petioles nearly as long; flower clusters dense, axillary; 

 calyx-teeth 10, subulate, hooked at the apex, hardened in fruit; corolla white. 



Introduced in waste places; native of Europe. 



435. LEONURUS. MOTHERWORT. 



Erect herbs with cut-lobed leaves; flowers in axillary whorls; 

 calyx 5-nerved, with 3 nearly equal teeth; corolla bilabiate, the 

 upper lip oblong, entire, somewhat arched, the lower spreading, 

 3-lobed, the middle lobe larger, narrowly oblong-obovate, entire, 

 the lateral ones oblong. 



Leonurus cardiaca L. Perennial; somewhat puberulent; stems stout, 

 erect, 1-1.5 m. high; leaves long-petioled, orbicular to oblong-lanceolate, 

 palmately 3-5-cleft, the lobes acute; flower clusters dense; calyx-teeth 

 subulate, as long as the tube; corolla purplish or white, 6-10 mm. long, the 

 upper lip bearded. 



In waste places, introduced from Europe. 



436. PHYSOSTEGIA. 



Smooth erect perennial herbs; leaves sessile, lanceolate or 

 oblong, mostly serrate; flowers large and showy, opposite, crowd- 

 ed in simple or panicled terminal leafless spikes; calyx obscurely 

 10-nerved, short-tubular or bell-shaped, more or less enlarged and 

 slightly inflated in fruit; corolla funnelform, with a much inflated 

 throat, bilabiate; upper lip erect, nearly entire; lower lip 3-parted, 

 spreading, small, the middle lobe larger, broad and rounded, 

 notched. 



Physostegia parviflora Nutt. Glabrous; stems erect, 30-90 cm. high, 

 mostly simple; leaves lanceolate to ovate-lanceolate, acute or the lower ones 

 obtuse, sharply serrate, sessile or nearly so, 6-10 cm. long; spikes many- 

 flowered; bracts ovate, acute, shorter than the calyx; calyx-teeth short; corolla 

 purple, 12 mm. long. 



In moist places, especially river-banks and lake shores, rare in our limits. 



437. LAMIUM. DEAD NETTLE. 



Decumbent herbs; calyx tubular-bell-shaped, about 5-nerved, 

 with 5 nearly equal awl-pointed teeth; corolla 2-lipped, dilated 

 at the throat, the tube longer than the calyx; upper lip 

 arched, narrowed at the base, the middle lobe of the spreading 

 lower lip broad, notched at the apex, contracted at the base; 

 lateral lobes small, at the margin of the throat; stamens 4, 

 ascending under the upper lip; the lower pair longer. 



Upper leaves clasping. L. amplexicaule. 



Leaves ovate, petioled. L. maculatum. 



