OP ARTS AND SCIENCES. 85 



L-apitulo scepius unico subpedunculato ; involucri bracteis lanceolatis, 

 intimis linearibus acutiusculis ; pappo radio et disci conformi e setis 

 gracillimis elongatis. Bull. Torr. Club, vi. 163, & Bot. Gazette, iii. 

 50. — Colorado and Indian Territory, E. K. Smith, Dr. Wilcox, and 

 Arizona, Lemmon. 



T. RoTHROCKii, Gray. Foliis lato-spathulatis brevibus circa ca- 

 pitulum sessile rosulato-confertis ; involucro breviore latiore, bracteis 

 oblongis plerumque obtusis ; pappus radii e setulis squamellatis latitu- 

 dinem achenii baud excedentibus, nunc 1 vel 2 longioribus. Roth- 

 rock in Wheeler Rep. vi. 148, t. 7. — Alpine region of the mountains 

 around South Park, Colorado, Rothrock. 



++ ++ Capitula raajuscula (f-^— pollicaria), plerumque seseilia ; involu- 

 cro pluriseriatim imbricato : pappus radii saepius j^lurisetosus : plantae 

 sericeo- vel striguloso-pubescentes, radice perenni, T. incana forte 

 excepta. 



T. SERiCEA, Hook. Depresso-acaulescens, demum multiceps et 

 pulviniformis ; foliis linearibus sen lineari-spathulatis circa capitulum 

 (pollicare vel minus) arete sessile confertis eumque jequantibus vel 

 superantibus ; bracteis involucri angusto-lanceolatis plerisque acutis ; 

 ligulis albis vel purpureo tinctis ; pappo ssepius conformi plurisetoso 

 (forma papposa. Gray, PI. Fendl. 69), vel radii pauci-setoso, vel 

 breviore validiore, vel squamellato latitudinem achenii parum exce- 

 dente. Fl. Bor.-Am. ii. 16, t. 119 ; Mechan, Flowers, ser. 2, i. t. 47. 

 Aster ? exscapus, Richards. — Saskatchewan and Rocky Mountains, 

 lat. 54°, to New Mexico and Arizona ; fl. April and May. Very vari- 

 able in breadth of leaves, size of heads, &c. ; commonly with pappus 

 of ray and disk nearly alike, only at the North found with the ray- 

 pappus reduced, either to a few unequal aristiform bristles, as figured 

 by Hooker, or to a circle of setiform squamellse. In one form the 

 heads are only half an inch long. 



Var. LEPTOTES (an spec. ?) : forma ambigua ; capitulis vix semipolli- 

 caribus, priraario sessili, sequentibus subpedunculatis ; foliis angustis. 

 — Middle Park, Colorado, Parry. 



T. Arizonica. Depresso-subcaulescens, multicipiti-ramosa, 2-3- 

 poUicaris, pube minuta sericeo-canescens ; foliis spathulatis brevibus 

 (semipollicaribus) capitulum parum sessile hemisphgericum (semipolli- 

 care) fulcrantibus vix superantibus ; bracteis involucri lanceolatis ple- 

 rumque obtusis ; pappo radio et disci conformi e setis rigidiusculis 

 achenio (lin. 2-3 longo) asquilongis. — Arizona, at Fort Trumbull, &c., 

 Palmer. 



