338 ACANTIIACEJE. (ACANTHUS FAMILY.) 



25. MELAMPYRUM, Tourn. COW-WHEAT. 



Calyx bell-shaped, 4-cleft; the taper lobes sharp-pointed. Tube of the co- 

 rolla cylindrical, enlarging above; upper lip arched, compressed, straight in 

 front; the lower erect-spreading, biconvex, 3-lobed at the apex. Stamens 4, 

 under the upper lip : anthers approximate, oblong, nearly vertical, hairy ; the 

 equal cells minutely pointed at the base. Ovary with 2 ovules in each cell. 

 Pod flattened, oblique, 1 - 4-seeded. Erect branching annuals, with opposite 

 leaves, the lower entire, the upper mostly larger and fringed with bristly teeth 

 at the base. Flowers scattered and solitary in the axils of the upper leaves in 

 our species. (Name composed of p.e\as, black, and Trupos, wheat ; from the color 

 of the seeds of field species in Europe, as they appear mixed with grain.) 



1. M. Americanum, Michx. Leaves lanceolate, short-petioled, the lower 

 entire ; the floral ones similar, or abrupt at the base and beset with a few bristly 

 teeth ; calyx-teeth linear-awl-shaped, not half the length of the slender tube of 

 the pale greenish-yellow corolla, (M. pratense, var. Americanum, Benth.) 

 Open woods: common. June -Sept. Plant 6' -12' high. Corolla 5" long, 

 more slender than in M. pratense, sometimes tinged with purple. 



ORDER 69. ACANTHACEJE. (ACANTHUS FAMILY.) 



Chiefly herbs, with opposite simple leaves, didynamous or diandrous sta- 

 mens, inserted on the tube of the more or less 2-lipped corolla, the lobes of 

 which are convolute or imbricated in the bud; fruit a 2-celled and few- (4- 

 12-) seeded pod ; seeds anatropous, without albumen, usually flat and sup- 

 ported by hooked projections of the placentae. Flowers commonly much 

 bracted. Calyx 5-cleft. Style thread-form: stigma simple or 2-cleft. 

 Pod loculicidal, usually flattened contrary to the valves and partition. 

 Seed with albumen in Elytraria of the Southern States, according to Dr. 

 Feay. Cotyledons broad and flat. Mucilaginous and slightly bitter, not 

 noxious. A large family in the warmer parts of the world : represented 

 in gardens by THUNBERGIA, which differs from the rest by the globular 

 pod and seeds, the latter not on hooks (retinacula) ; in the Northern States 

 by only two indigenous genera. 



1. DIANTHERA, Gronov. WATER-WILLOW. 



Calyx 5-parted. Corolla deeply 2-lipped ; the upper lip erect, notched ; the 

 lower spreading, 3-parted, external in the bud. Stamens 2 : anthers 2-celled, 

 the cells separated and somewhat unequal. Pod obovate, flattened, contracted 

 at the base into a short stalk, 4-seeded. Perennial herbs, growing in water or 

 wet places, with entire leaves, and purplish flowers in axillary peduncled spikes 

 or heads. (Name formed of 8i's, double, and dvdrjpd, anther; the separated cells 

 giving the appearance of two anthers on each filament.) 



1. D. Americana, L. . Leaves linear-lattceolate, elongated; spikes ob- 

 long, dense, long-peduncled. (Justicia pedunculosa, Michx. Rhytiglossa, Nees.) 

 Borders of streams and ponds, N. W. Vermont to Wisconsin, Virginia, and 

 southward. July - Sept. 



