302 ACANTHACE^E. (ACANTHUS FAMILY.) 



spreading, biconvex, with three short lobes. Stamens 4, didynamous, under the 

 upper lip : anthers approximate, oblong, hairy ; the cells nearly equal, slightly 

 pointed at the base. Ovary with 2 ovules in each cell. Capsule compressed, 

 oblique, loculicidally 2-valved, 1 - 4-seeded. Annual herbs, with opposite lan- 

 ceolate or linear leaves, and solitary axillary flowers. 



1. M. Americanum, Michx. Stem naked below, leafy and commonly 

 branched above the middle ; leaves lanceolate, entire, short-petioled ; the upper 

 ones broader and sharply toothed at the base ; flowers greenish-yellow. Dry 

 woods along the mountains, Georgia, and northward. Aug. Stem 6' - 1 2' 

 high. Leaves 2' long. Flowers 4" - 5" long. 



ORDER 92. ACAJVTHACE^]. (ACANTHUS FAMILY.) 



Chiefly herbs, with opposite (rarely alternate or clustered) undivided 

 exstipulate leaves, and bracted, often showy flowers. Calyx 5-parted. 

 Corolla more or less bilabiate, 5-lobed, twisted in the bud. Fertile sta- 

 mens 2 or 4, inserted on the tube of the corolla : anthers 2-celled. 

 Ovary free. Style single : stigma entire or 2-lobed. Capsule loculici- 

 dally 2-valved, 2-celled, 4 - several-seeded, opening elastically. Seeds 

 anatropous, flat, rounded, without albumen, mostly supported by curved 

 appendages of the placentae. Radicle inferior. Stems commonly swol- 

 len between the joints. 



Synopsis. 



* Capsule oblong, bearing the seeds at the base. Appendages of the placentae none. 

 1. ELYTRARIA. Spike borne on a closely-bracted scape. Leaves radical. 



* * Capsule club-shaped, bearing the seeds above the base, appendaged. 

 2- DIPTERACANTHUS. Corolla nearly regular.^ Stamens 4. Flowers axillary, solitary or 

 clustered. 



3. DIANTHERA. Corolla bilabiate. Stamens 2. Cells of the anthers placed one lower than 



the other. Flowers in long-peduncled axillary spikes. 



4. DICLIPTERA. Corolla bilabiate, resupinate. Stamens 2. Cells of the anthers placed 



one behind the other. Flowers in leafy -bracted heads or clusters. 



1. ELYTRARIA, Vahl. 



Calyx 4 - 5-parted, the lateral lobes narrower. Corolla salver-shaped or 

 bilabiate, 5-lobed. Fertile stamens 2, the 2 anterior ones sterile : anther-cells 

 parallel. Stigma 2-cleft. Capsule sessile, about 8-seeded ; the seeds fixed near 

 the base of the capsule, without appendages. Low herbs. Leaves all radical, 

 clustered. Scape covered with imbricated bracts. Flowers spiked, 2-bracted. 



1 E. virgata, Michx. Leaves oval or oblong, narrowed downward, 

 entire or wavy on the margins, smooth or pubescent ; bracts of the scape 

 alternate, rigid, lanceolate, acuminate, clasping; those of the spike ovate; 

 corolla white, salver-shaped, the lobes nearly equal ; capsule cylindrical. 

 Banks of rivers, Florida to South Carolina. Aug. y. Scapes 6'- 12 high 

 Leaves 2' - 4' long. 



