302 ACANTHACEJE. (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' -12' 

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



ORDER 92. ACANTHACE^E. (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 



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. ELYTEABIA, Vahl. 



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

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

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

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

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



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

 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. 1J. Scapes 6'- 12' high. 

 Leaves 2' - 4' long. 



