PENTAD DRIA. DIGYNIA. 189 



pears to have been very complete, and collected also by a 

 botanist, I dare not for the present announce it as a dis- 

 dinct species. This genus appears to be somewhat allied 

 to Sison, but certainly distinct. To Hydrocotyle it can 

 have no pretensions. 



274. CENANTHE. X. (Water Dropwort, Fili- 

 penJula.) 



^i Fruit ovate-oblong, corticate, solid, apex 

 denticulate, crowned with the persistent style, 

 ridges (or striai) (on each seed) 3 or 5 obtuse. 

 Universal involucrum scarcely any,"SpRENGEL. 



Umbell formed of few rays; umbellets subglobose, with 

 the flowers often sessile. Invohicell many-leaved. Poi- 

 sonous plants, mostly aquatic, having roots with pendu- 

 lous tubers, fistulous striated stems, and pseudo-pinnated 

 leaves, commonly twice compounded near the root, often 

 laciniated, segments mostly entire on the margin. . 



Species. 1. (E. carolinensis. -\- 2. Phellar.driiim. Lam. 

 DecandoUe. Plielkmdrium ngualicum. L. Hab. On the 

 llocky Mountains? Ph. 3. rigida. Leaves all? pseudo- 

 pinnate; leaflets sessile, oblong-lanceolate, entire or in- 

 cisely toothed; involucrum none; styles peltately dilated 

 at the base, extremely short; fruit subelliptic. Obs. 

 Stem erect, rigid, terete, even, striate, and fistulous. 

 Leaflets 4 or 5 pair, all sessile, circumscribed by a whitish 

 and somewhat scabrous margin. Involucell about 8- 

 leaved, subulate. Calix 5-toothed, acute. Petals cor- 

 dately inflected: many of the central sessile flowers ste- 

 rile. Styles persistent, peltately dilated at the base, 

 scarcely' a line in length, divaricate, obtuse or rather 

 trxmcate, and distinctly grooved on tlie upper side. Fruit 

 elK^ftic-ovate, dorsally compressed, flat, (as in Pastinaca 

 sativa) Seeds rather large, with a suberose prominent 

 subalated margin continued inwards so as to cover the 

 seed, slenderly striated on the back; strise 5. 



Slum rigi dins. Willd. sp. pi. 1. p. 1433. Pursh, Flor. 

 Am. 1. p. 194. Probably Sison marginatum. Mich. Fl. 

 Am. 1. p. 168. 



3. *amlngua. Stem even, with few leaves; leaves all 

 pseudo-pinnate, leaflets three to five pair; narrow-linear, 

 long and entire, all sessile and acute, under side glau- 

 cous; involucrum 2 or 3-leaved; umbell$ terminal, near- 

 ly solitary. Obs. Root perennial, tuberous? Stem tall, 

 smooth, striate, fistulous and cylindric. Leaves dis- 

 tant, with small sheaths, only about 4 or 5 on the whole 



