MONOPETALOUS EXOGENOUS PLANTS. 401 



seeds auatropous, flat, rounded, without albumen, mostly 

 supported by curved appendages of the placentae ; radicle 

 inferior. Stems commonly swollen between the joints. 



SYNOPSIS. 



* Capsule oblong, bearing the seeds at the base; appendages of the placentoe none. 



Spike boi'ne on a dosely-lrracted scape. Leaves radical Elytra ri a. 



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

 Corolla nearly regular. Stamens 4. Flowers axillajy, solitary or clustered. 



DiPTERACANTHUS. 



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

 Flowers in long-peduncled axillary spikes Dianthera. 



Corolla bilabiate, resupinate. Stamens 2. Cells of the anthers placed one behind the 

 other. Flowers in leafy-bracted heads or clusters Dicliptera. 



ELYTEARIA, 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 lierhs ; 

 leaves all radical, clustered ; scape covered with imbricated 

 bracts ; floivers spiked, 2-bracted. 



E. viRGATA, Michx. Leaves oval or oblong, narrowed 

 downward, entire or wavy on the margins, smooth or pu- 

 bescent; Iracts of the scape alternate, rigid, lanceolate, 

 acuminate, clasping, those of the spike ovate ; corolla 

 white, 5aZver-shaped, the lobes nearly equal ; capsule cylin- 

 drical. Scapes &-!%' high ; leaves 2-4' long. 



DIPTERACANTHUS, Nees. 



Calyx 2-bracted, 5-parted, with linear or bristle-like 

 lobes; corolla funnel-shaped, 5-lobed, the lobes equal, 

 rounded ; stamens 4, didynamous, included ; anthers sagit- 



