PENTANDRIA, DIGYNIA. 189 
pears to have been very complete, and collected also"by a 
botanist, | dare not for the present announce it asa dis- _ 
dinct species. This genus appears to be somewhat allied _ 
to Sison, but certainly distinct. To Hydrocotyle it can , 
have no pretensions. idan rs ae 
274. G@ENANTHE. L. (Water Dropwort, Fili- 
pendula.) ae ee: Waeace 
“Fruit ovate-oblong, corticate, solid, apex 
denticulate, crowned with the persistent style, 
ridges (or stria) (on each seed) 3 or 5 obtuse. 
Universal involucrum scarcely any.” SPRENGEL. 
Umbell formed of few rays; umbellets subglobose, with 
the flowers often sessile. “Involucell 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. @. carolinensis. + 2. Phellandrium. Lam. 
Decandolle. Phellandrium aquaticum. L. Han. On the 
Rocky Mountains? Px. 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. Qss. 
Stem erect, rigid, terete, even, striate, and fistulous, 
Leaflets 4 or 5 pair, all segiiie, <ipcuieeceoed a ane 
_ and somewhat scabrous margin. Involucell about 8-— 
~ leaved, subulate. Calix 5-toothed, acute. Petals cor- 
dately inflected; many of the central sessile flowers ste- 
i Styles persistent, peltately dilated at the base, 
scarcely a line in length, divaricate, obtuse or rather _ 
truncate, and distinctly grooved on the upper side. Fruit 
elliptic-ovate, dorsally compressed, flat, (as in Jastinaca 
sativa.) Seeds rather large, with a suberose prominent 
subalated margin continued inwards so as to cover the 
seed, slenderly striated on the back; striz 5. Soe 
Sium rigidius, Willd. sp. pl. 1. p. 1433. Pursh, Flor, 
Am. 1. p. 194 Probably Sison manginatum. Mich. Fl, 
Am. 1. p. 168. eek . 
3. *ambigua, Stem even, with few leaves; leaves all 
pseudo-pinnate, leaflets three to five pair; narrow-linear, 
jong and entire, all sessile and acute, under side glau- 
cous; involucrum 2 or 3-leaved; umbells terminal, near- 
ly solitary. Oxs. Root perennial, tuberous? Stem tall, _ 
“smooth, striate, fistulous and cylindric. Leaves dis- ~ 
ie. Leaves Cie- 
_jant, with small sheaths, only about 4 or 5 on the whole 
ase 
~ 
