188 PENTANDRIA. DIGYNIA. 



pressed. Seed gibbously convex, marked with 

 3 striae; commissure narrow, immarginate, flat. 

 Involucrum none. 



Umbell imperfect; umbellulae about 4, 3 to 5-flowered; 

 involucell unequal, 3 to 5 or 6-parted; leaf solitary, radi- 

 cal, biternate, seg-ments multifid; scapes furnishing a corv- 

 similar involucrate leaf; flowers stellate; root a globular 

 tuber. 



E. biildom. 



SisG7i huHiosum, Mich. 1. p. 169. Jlydrocotyle composita, 

 Pursh, Flor. Am. 1, p. 190. //. arnb/gua, of the same, 2. 

 p. 732. H. bipinnata. Muhlenberg's Catalogue. 



Obs. Candex ascendant, about an incli high. Leaf soli- 

 tary, emitting 2 and sometimes 3 scapes from its sheath; 

 lamina biternately divided, partitions subteniate; seg- 

 ments subrhomboidal, cleft, ultimate lobes ti-ifid, obtuse, 

 with minute points. Scapes round, 4 to 5 inclies higli, 

 terminating in an irregular umbell of 3 or 4 rays, subtend- 

 ed at the base by a sessile ternate leaf subdivided simi- 

 larly to that of the root. Leaves of the involucell entire, 

 simple, linear-oblong. Flowers white, slcllately expand- 

 ing. Petals obovate-oblong, or attenuated downwards so 

 as to a]:)pear unguiculate. Calix obsolete, marginal. Sta- 

 mina, filaments erect, exserted long'er tiian the petals, 

 anthers oval, deep brown. Styles subulate, persistent, 

 twice the length of the germ; stigmas obsolete. Germ 

 turbinate, laterally compressed, truncated above. Seed 

 gibbously convex, marked, with 3 curved lines, (my spe- 

 cimens were not sufficiently advanced to determine the 

 ultimate character of the seed) 2 lateral and 1 dorsal, the 

 margin of the commissure being inconspicuous and form- 

 ing nearly a right line. 



Mab. lu shady alluvial soils, std)ject to inundation. 

 Near Lancaster, Pennsylvania; near Pittsburgh; on the 

 Ohio, Missouri, 'I'ennessee, 8;c. 



Of tins genus there are probably 2 species, but tlie 

 second has not been indicated; Mr. Pursh's Hifdrocotyle 

 amlicrua 1 have now before me, which is unqucstionabiy 

 the i)iant described by Michaux tmder Sison, and uhicii 

 he liimseif has also given as H. composita. A second spe- 

 cies? of which I have merely an accurate drawing made 

 by C W. Short, M.D. from a living specimen found on 

 the banks of Kentucky river the loth of March, has to ali 

 appearance leaves which are simply ternate, with the di- 

 visions 3-parted, the lobes subrhomboidal with dentures 

 Avhich are a little cleft. And althougii the specimen ap- 



