372 CLASS XXI. ORDER VIII. 



Syn. Ceratophyllum demersum. Pursh. 



An aquatic, submersed plant like some of the Myriophylla. 

 Stems slender, branched, floating. Leaves whorled, linear di- 

 chotoinous, toothed on the beak. Flowers axillary, sessile, ob- 

 scure. Fruit armed with the persistent style, and usually two 

 other spines. It has been considered a variety of C. demersum of 

 Europe. 



386. ARUM. 

 Arum triphyllum. L. Dragon Root. Indian Turnip. 



Stemless ; leaves trifoliate ; leafets oval, entire. 

 Mich. 



American Medical Botany, PI. iv. 

 A singular and not inelegant plant, native of our swamps and 

 wet woods. The root is round and flattened, its upper part tu- 

 nicated like the onion, its lower and larger portion tuberous and 

 fleshy, giving off numerous, long, white radicles in a circle from 

 its upper edge. It is covered on the under side with a dark, 

 loose, wrinkled skin. Leaves usually one or two, on long, sheath- 

 ing footstalks, composed of three oval, mostly entire, acuminate 

 leafets, which are smooth, paler on the under side, and becoming 

 glaucous as the plant grows older, the two lateral ones somewhat 

 rhomboidal. Scape erect, round, green or variegated with pur- 

 ple, invested at base by the petioles, and by acute sheaths. This 

 supports a large, ovate, acuminate spathe, convoluted into a 

 tube at bottom, but flattened and bent over at the top, like a 

 hood. Its internal color is exceedingly various, even in plants 

 growing together. In some it is wholly green, in others, dark 

 purple or black. In most, it is variegated, with pale greenish 

 stripes on a dark ground. The spadix is much shorter than the 

 spathe, club, shaped, rounded at the end, green, purple, black 

 or variegated, suddenly contracted into a narrow neck at base, 

 and surrounded below by the stamens or germs. In the barren 

 plants its base is covered with conical, fleshy filaments, bearing 

 from two to four circular anthers each. In the fertile plants it 

 is invested with roundish, crowded germs, each tipped with a 

 stigma. Plants which are perfectly moncEcious, and which are 

 the least common, have stamens below the germs. There are 



