AND GENERA OF PLANTS. 417 



Lagothamnus * amUguus; with the whole aspect and character of the pre- 

 ceding, but with the divisions of the involucrum all obtuse; the false pappus of 

 the sides of the achenium more copious, and the inner true pappus so slender 

 as to be scarcely distinguishable. 



Hab. With the above. 



Appendix to Senecionide^. Subtribe MELAMPODINE^. 



Division ii. Millerie^ ? 



*PICROTHAMNUS. 



Capitulum monoicous, heterogamous, few-flowered; rays feminine, (three to 

 five,) tubular, truncated, two or three-toothed; discal florets masculine, with 

 abortive styles, (five to ten,) globose-ovate, five-toothed, teeth triangular, and, 

 as well as the rays and achenium, copiously clothed with long flaccid hairs, 

 the tube very slender. Receptacle naked, very small. Involucrum hemi- 

 spherical, imbricate, about five-leaved, the leaves rounded. Style bifid, 

 stigmas terete-cylindric, with a minutely pencillated summit, nearly smooth. 

 Achenium obconic, turbinate, subcylindric, without pappus, sending off!, up- 

 wards, numerous long, tortuous hairs. Discal florets without any rudiments 

 of fruit. — A low, much-branched, inelegant, spiny shrub, somewhat softly 

 lanuginous. Leaves alternate, twice trifid. With the habit of an Artemisia; 

 capituli in short, leafy racemes, the rachis of which, at length, becomes a 

 long spine. Florets pale yellow. — (The name from riixpos, bitter, and Ba(ivos, 

 a hush; in allusion to its bitterness. ) 



Picrothamnus * desertorum. 



Hab. Rocky Mountain plains, in arid deserts, towards the north sources of the Platte. Root 

 woody, much branched and very long, covered with numerous fibrous vestiges of bark. Stem 

 from four inches to a foot or more, woody and branched from the base ; the whole plant hirsute 

 and grayish canescent. Leaves twice trifid, pseudopetiolate, the segments short, oblong, and entire. 

 A plant of very doubtful affinity, allied in some respects to Clibadium, and therefore to the division 

 MiLLERiE^. It is also allied to the IvE.a;; but the tube of anthers are united. 



VII. — 5 E 



