COMPOSITE. (COMPOSITE FAMILY.) 257 



sharply serrate in the middle, very rough both sides and rugose-veined, closely 

 sessile (2-3' long), nearly equal; scales of the bell-shaped involucre oblong, ap- 

 pressed, with very short and slightly spreading herbaceous tips ; achenes smooth. 



Bogs and low grounds, Del. to Maine and northward, near the coast ; also 

 Pocono Mountain, Penn. A dwarf form (var. STRf CTUS, Gray) has oblong- to 

 linear-lanceolate nearly entire leaves, and usually solitary heads ; White Moun- 

 tains, N. H., to Lab. Aug. Kays light violet. Involucre nearly smooth, 

 except the ciliate margins. 



* 2. Involucre and usually the branchlets viscidly or pruinose-glandular, well 

 imbricated or loose ; pubescence not silky ; leaves entire (or the lower with 

 few teeth), the cauline all sessile or clasping ; rays showy, violet to purple. 

 H- Heads small ; involucre not squarrose. Extreme western. 



9. A. FSndleri, Gray. Rigid, 1 high or less; leaves firm, linear, 1- 

 nerved, hispid-ciliate, 1' long or mostly much less; heads scattered, 3" high; 

 scales linear-oblong, obtuse, or the inner acute. Central Kan. (Ellis, Dr. L. 

 Watson) and southwestward. 



H- 4- Heads larger ; involucral scales spreading, in few or many ranks. 



10. A. grandifldrilS, L. Rough with minute hispid hairs ; stems slender, 

 loosely much branched (1-3 high); leaves very small (i-l x long), oblong- 

 linear, obtuse, rigid, the uppermost passing into scales of the hemispherical 

 squarrose many-ranked involucre; rays bright violet (Y long) ; achenes hairy. 



Dry open places, Va. and southward. Heads large and very showy. 



11. A. Oblongifdlius, Nutt. Minutely glandular-puberulent, much 

 branched above, rigid, paniculate-corymbose (1-2 high) ; leaves narrowly ob- 

 long or lanceolate, mucronate-pointed, partly clasping, thickish (1-2' long by 

 2-5" wide); involucral scales nearly equal, broadly linear, appressed at the 

 base; rays violet-purple; achenes canescent. Banks of rivers, from Penn. 

 and Va. to Minn, and Kan. Heads middle-sized or smaller. 



Yar. rigidulus, Gray. Low, with more rigid and hispidulous scabrous 

 leaves. In drier places, 111., Wise., and southwestward. 



12. A. NdvSB-Anglise, L. Stem stout, hairy (3 - 8 high), corymbed at 

 the summit ; leaves very numerous, lanceolate, entire, acute, auriculate-clasping , 

 clothed with minute pubescence, 2-5' long ; scales nearly equal, linear-awl-shaped, 

 loose, glandular-viscid, as well as the branchlets ; rays violet-purple (in var. 

 R6SEUS rose-purple), very numerous ; achenes hairy. Moist grounds ; com- 

 mon. Heads large. A peculiar and handsome species. 



13. A. mod&stus, Lindl. Pubescent or glabrate ; stem slender, simple, 

 with few large heads terminating slender branchlets ; leaves lanceolate, very 

 acute, narrowed to a sessile base, sparingly serrate or serrulate ; scales linear- 

 attenuate, equal, mostly herbaceous ; rays blue. N. Dak. and westward. 



* 3. Leaves whitened, silvery-silky both sides, all sessile and entire, mucronulate ; 

 involucre imbricated in 3 to several roivs ; rays showy, purple-violet. 



14. A. sericeus, Vent. Stems slender, branched; leaves silver-white, 

 lanceolate or oblong , heads mostly solitary, terminating the short branchlets ; 

 scales of the globular involucre similar to the leaves, spreading, except the short 

 coriaceous base ; achenes smooth, many-ribbed. Prairies and dry banks, Wise, 

 and Minn, to Ky., and southward. Heads large ; rays 20-30. 



