LABIAT^E. (MINT FAMILY.) 325 



2. M. alba, n. sp. Smooth or hirsute ; leaves wedge-lanceolate or oblong, 

 toothed, rounded at the apex narrowed to the sessile base ; the lowest oblong, 

 tapering into a slender petiole ; the floral ones ovate or orbicular, obtuse ; whorls 

 4-flowered ; calyx nerveless, with the two larger lobes notched ; corolla white, 

 the upper lip emarginate. Low pine barrens, West Florida, near the coast. 

 July and Aug. Stem 1 - l high. Leaves 2' long, or the radical ones 4'- 5' 

 long, and, like the calyx and corolla, thick and somewhat fleshy. 



22. PHYSOSTEGIA, Benth. 



Calyx tubular-bell-shaped, inflated in fruit, nearly equally 5-toothed. Corolla 

 tubular-funnel-shaped, 2-lipped ; the upper lip erect, concave, entire or notched, 

 the lower spreading, broadly 3-lobed. Stamens 4, ascending under the upper 

 lip : anthers approximate, with the cells parallel, ciliate. Nutlets smooth, 

 acutely 3-angled. Smooth perennial herbs, with erect mostly simple stems, 

 and opposite showy purplish flowers, in terminal spikes or racemes. 



1. P. Virginiana, Benth. Leaves large (6' -9' long), oblong, sharply 

 serrate, the lowest narrowed into a petiole ; spikes thick, dense-flowered ; calyx- 

 teeth acute ; corolla 1' long. (Dracocephalum Virginianum, Z.) Varies through 

 several intermediate forms, including Dracocephalum varicgatum, Vent., and D. 

 obovatum, Eli, into var. DENTICULATA, with lanceolate or linear denticulate or 

 entire leaves, and smaller (6"- 9" long) flowers in a long loosely flowered spike. 

 Low ground and swamps, Florida to Mississippi, and northward. June- 

 Aug. Stem 2 - 4 high. Racemes simple or compound. 



23. LAMIUM, L. DEAD-NETTLE. 



Calyx tubular-bell-shaped, 5-nerved, nearly equally 5-toothed, the teeth subu- 

 late, not spiny. Corolla slender, dilated at the throat, 2-lipped ; the upper lip 

 ovate or oblong, narrowed at the base ; the lateral lobes small, at the margins of 

 the throat ; the lowest lobe large, notched, contracted at the base into a short 

 stalk. Stamens 4, ascending under the upper lip : anther-cells at length spread- 

 ing. Nutlets 3-angled, truncate at the apex. Herbs. Leaves incised ; the 

 lower ones petioled, the floral ones sessile, longer than the dense whorls. 



1. L. amplexicaule, L. Leaves orbicular, incisely crenate-lobed ; the 

 floral ones clasping, the others long-petioled ; tube of the corolla straight, the 

 lateral lobes truncate ; anthers hairy. Cultivated ground and waste places, 

 common. May. (I) Stems 4' -12' high. Corolla small, purple, often im- 

 perfectly developed. 



24. MARRTJBIUM, L. HOREHOUND. 



Calyx tubular, 5-10-nerved, nearly equally 5- 10-toothed; the teeth spiny, 

 mostly spreading in fruit. Corolla-tube included in the calyx, 2-lipped ; the 

 ripper lip erect ; the lower 3-lobed, with the middle lobe largest. Stamens 4, 

 included : anther-cells diverging. Lobes of the style short, obtuse. Nutlets 

 obtuse at the apex. Chiefly tomentose or woolly perennial herbs, with rugose 

 leaves, and axillary whorls. 

 28 



