216 HYPERICACE^E. 



septicidally three-valved. Seeds very numerous, horizontal, 

 oblong ; the crustaceous testa minutely striate and scrobicu- 

 late ; the inner integument fleshy. Albumen none. Em- 

 bryo conformed to the seed, cylindrical : cotyledons at the 

 apex remote from the hilum, much shorter than the radicle. 

 Herbs very smooth and pale green, with perennial roots, 

 terete and branching stems, and decussately opposite oval or 

 oblong entire leaves, which are sessile by a broad and some- 

 what clasping base, or else narrowed into a short petiole, 

 punctate with translucent and larger dark -colored dots. 

 Flowers small, cymulose ; the contracted cymes axillary 

 and terminal, much shorter than the leaves : petals flesh-col- 

 ored, or somewhat orange-colored in fading. Capsules much 

 larger than the calyx, the pericarp filled with resiniferous 

 lines. 



Etymology. Name from i\m&r]s, growing in marshes, from the station 



these plants inhabit. 



I 



Geographical Distribution, &c. A well-marked genus of two spe- 

 cies, natives of Eastern North America from Canada to Florida and Texas. 



PLATE 94. Elodea Virginica, Nutt. ; — summit of a flowering plant, 

 of the natural size. (Cambridge, Massachusetts.) 



1. Diagram of the flower, Estivation, &c. 



2. Open flower, enlarged. , 



3. One of the three phalanges of the stamens, magnified ; inside view. 



4. Anther, &c, more magnified, outside view ; and 5, inside view. 



6. Pistil and receptacle, magnified. 



7. An ovule, highly magnified. 



8. A capsule, with the persistent calyx and filaments at the base, enlarged. 



9. A magnified seed. 



10. Vertical section of the same and of the contained embryo. 



