AND GENERA OF PLANTS. 329 



(jaule, acute; stem smooth, except towards the summit; flowers in an irregular 

 corymb; rays about ten to twelve, as long as the disk; scales of the involucrum 

 linear-lanceolate, smooth; achenium pubescent 



Hab. The central chain of the Rocky Mountains, in forests. S. multiradiata. Hook., Vol. II., 

 p. 5, not of Aiton. Closely allied to S. multiradiata, for which it appears to be taken by Hooker 

 in Flor. Bor. Am., Vol. II., p. 5, but is, in fact, nearer to some varieties of S. Virga-Aurea, having 

 pubescent achenia. 



*PRIONOPSIS. 



(ApLOPAPPUs. Section I. Leiachenium, Decand. in part.) 



Capitulum hemispherical, many-flowered; rays numerous, (two or more series,) 

 entire, feminine. Discal florets slender and cylindric, mostly abortive. Stig- 

 mas of the ray smooth and very slender, scarcely exserted ; those of the disk 

 pubescent, rather short, filiform and obtuse, somewhat compressed. Recep- 

 tacle slightly alveolate, flat. Involucrum imbricated, of many series of some- 

 what agglutinated, squarrose sepals, with leafy points. Achenium short and 

 smooth, cylindric-ovoid, contracted at the summit; pappus rigidly setose, 

 longer than the florets, scabrous, unequal, about ten of the setae longer and 

 thicker; pappus of the ray shorter and of fewer rays, deciduous. — A stout, 

 herbaceous biennial, with the habit and entire aspect of Grindelia glutinosa; 

 leaves alternate, ovate, obtuse, very conspicuously and distinctly serrate- 

 ciliate; flowers wholly yellow, large, fastigiate; branchlets one-flowered. — 

 (The name from tsptoj^, a saw, and oi^ts, resemblance, in allusion to the ele- 

 gant serratures of the leaves. ) 



Prionopsis ciliata. Donia ciliata, Nutt. Aplopappus ciliatus, Decand., Vol. 

 v., p. 346. When the fruit is mature the pappus is so deciduous that the 

 achenium may be supposed naked, it being thrown off", or nearly so, by the 

 enlargement of the fruit, with which it does not progress in growth. 



APLOPAPPUS. (Cassini.) 



Capitulum many-flowered, radiate; liguli feminine, in one series; discal florets 

 hermaphrodite, fertile, five-toothed, tubular. Receptacle rather flat, foveo- 



VII.— -4 H 



