OF ARTS AND SCIENCES. 107 



Mexico, under the name of S. scabn'da, DC. — Var. canescens, of 

 S. W. Texas and S. New Mexico, is an outlying form, peihaps a 

 distinct species, which from its hoariuess and the broader bracts of 

 the involucre, might be confounded with narrower-leaved and soft 

 pubescent forms of S. nemoralis. — Var. Arizomca, the S. mollis, 

 Rothrock in Wheeler, Rep. vi. 14G, and in the heads approach- 

 ing the Mexican S. velutina, DC, is another ambiguous plant, with 

 low stems and comparativcl}' large heads, the thin involucral bracts 

 acutish ; of New Mexico and Arizona. 



= = Leaves obtuse, or abruptly apiculate or acutish, of firm or 

 coriaceous texture, the upper entire ; pubescence all close, cin- 

 ereous or canescent, or scabro-hispidulous ; the lateral ribs 

 commonly incomplete and not rarely obscure or even wanting : 

 panicle mostly compact : bracts of the involucre broadish^^ 

 obtuse, and of firm texture: rays rather few but large, golden 

 yellow. 



a. From cinereous to canescent with fine and soft or at length 

 minutely scabrous pubescence : leaves firm, but not rigid. 

 S. Californica, Nutt. *S'. velutina, var. panicula contracta, DC. 



The plant of Hfcnke is from Monterey, California, not Mexico. — 



Var. Nevadensis is hardly to be distinguished from the next species. 

 S. NEMORALIS, Ait. S. hispida, Mulil. in Willd. S. conferta, Poir. 



Diet. viii. 549. S. cinerascens, Schweinitz in Ell. S. decemjlora, 



DC. S. puberida, DC, not Nutt. — Var. incana. S. mollis, 



Bartl. in DC, &c. S. incana, Torr. & Gray. 

 S. NAXA, Nutt., of the Rocky INIountains, &c. ; has few and larger 



almost corymbosely disposed heads, and broader involucral bracts ; 



otherwise the larger forms are too like aS'. nemoralis. 



b. Hispidulous-scabrous, rigid, green. 



S. RADULA, Nutt. S. rotundifolia, DC. S. scaherrima, Torr. & 

 Gray, Fl. S. decemjiora, Gray, PI. Lindh., not DC. 



c. Scabro-puberulent, somewhat cinereous ; the very small leaves 

 with hardly any lateral ribs. 



S. SPARSiFLORA, Gray, Proc. Am. Acad. xii. 58. A var. subctn- 

 EREA, from S. Arizona, Lemmon, indicates an unsuspected relation- 

 ship with S. nemoralis. And, from the Mogollon Mountains, New 

 Mexico, Mr. Rusby sends a form between the latter and S. Cana- 

 densis, var. canescens. Further study of fuller materials is required. 



