COMPOSITE. (COMPOSITE FAMILY.) 161 



lower spatulate-linear, 2 to 4 inches long, I to 3 lines wide ; radical spatulate : 

 heads broad: involucral bracts linear-subulate; outer little shorter than inner. 



— Proc. Am. Acad. xvi. 99. A. encoicles, var. strictus, I'orter, Fl. Colorud. riG. 

 Common in the Colorado Rocky Mountains. 



-^ ■»- -t- The numerous small heads racemosdy arranged : unequal bracts well 

 imbricated, with squarrose or at least spreading herbaceous obtuse or merely mu- 

 cronate tips : cauline leaves small, linear and entire, scarceli/ narrowed at tlie 

 abrupt sessile or partly clasping base: akenes ranesrcnt-hirsulf : raijs uhii^, 

 rarely tinged with blue or purple. 



12. A. multiflorus, Ait. Low, a foot or two high, bushy-brunched, 

 cinereous or green : leaves rigid, scabrous-ciliate ; ujiperniost passing into m 

 volucral bracts ; these mostly with obtuse tips : heads in the ordinary forms 

 little over 2 lines long, and with only 10 to 15 or 20 rays. — From Arizona to 

 British Columbia and eastward across the continent. 



13. A. COmmutatus. A foot or so high, with divergent brandies : 

 heads more scattered and twice or even thrice the size of those of A. multijiorus, 

 3 or 4 lines high and broad : rays 20 to 30 : otherwise nearly as the preceding. 



— From Saskatchewan and the Dakotas to Utah and F. Oregon. 



■»-•»-•>-•»- Involucre in some imbricated and with short close tips, in others more 

 loose and herbaceous : heads when numerous either thyrsoid or open-pan ictUate 

 on erect or ascending branches. 

 ++ Cauline leaves sessile, but neither ivith cordate or aunculate base {with 1 or 2 



exceptions), nor ivith abrupt winged petiole-like lower portion. 

 =-■ Herbage inclined to be glabrous; the branches often pubescent in lines: leaves 

 {at least some of them) serrate or denticulate : stems branching and with sev- 

 eral to many heads : none alpine or subalpine : Eastern forms. 

 a. Involucre close and erect ; its bracts imbricated in successive lengths. 



14. A. paniculatus, Lam. Stem 2 to 8 feet high, freely and panicu- 

 lately branched : leaves from elongated oblong to narrowly lanceolate, mostlv 

 attenuate-acuminate, sharply serrate or denticulate, or upper entire, thin : heads 

 about J inch high, in loose and open mostly leafy panicles : bracts of the invo- 

 lucre narrowly linear, with tapering acute or acuminate fjreen tips: ravs 3 or 4 

 lines long, white varying to purplish or violet. — A very polymorphous species, 

 including also part of the forms heretofore included under A. Tradtscanti, 

 simplex, tenuifolius, and carneus. From E. Montana to Louisiana and east- 

 ward ; abundant in the Northeastern States. 



15. A. salicifolius, (Lam ?) Ait. Resembles the preceding, equally 

 branching : leaves commonly less elongated, less serrate or entire, of' firmer ti r- 

 fure, apt to be scabrous, and the fine reticulation of the veinlets maiiifcst : 

 involucre more imbricated; its bracts firmer, linear, j/v7/i shorter and more difi- 

 nite green tips, these acute or obtusish: heads disposed to be thi/rsoid or racemose- 

 glomerate on the ascending branches : rays purplish to violet, rarely white. — 

 Includes A. carneus, in ])art. F^rom E. Montana to To.xas and northeastward ; 

 most abundant in the Mississippi Valley. 



b. Involucre loose, and less imbricated ; its lirarts about equal. 



16. A. junceus, Ait. Slender, 1 to 3 feet high, the smaller plants sim- 

 ple-stemmed and with few heads, smooth and nearly glabrous : leaves linear or 



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