COMPOSITE. (COMPOSITE FAMILY.) 251 



w- *+ Leaves more or less plainly 3-ribbed ; heads in one-sided spreading or re- 

 curved racemes, forming an ample panicle. Not maritime. 

 = Smooth and glabrous, at least the stem and bright green leaves. 

 a. Leaves firm and rather rigid ; involucral scales thickish, obtuse, quite unequal. 



29. S. Missouriensis, Nutt. Smooth throughout (1- 3 high); leai-es 

 linear-lanceolate, or the lower broadly lanceolate, tapering tc, both ends, with 

 very rough margins ; teeth, if any, sharp and rigid; heads and dense crowded 

 racemes nearly as in u. 28 ; achencs nearly glabrous. Dry prairies, from Wise, 

 and Ind. south and westward. Heads 1-J 2" long. 



30. S. Shortii, Torr. & Gray. Stem slender, simple (2-4 high), mi- 

 nutely runghish-pubescent above; leaves (the larger 2 -3' long) oblong-lance- 

 olate, acute, the lower mostly serrate with a few fine teeth ; racemes mostly 

 short in a crowded panicle ; achenes silky-pubescent. Rocks at the Falls of 

 t.he Ohio ; Ark. A handsome species ; heads 3" long, narrow. 



b. Leaves thinner ; involucral scales thin, chiefly linear, obtuse. 



31. S. serotina, Ait. Stem stout (2-7 high), smooth, often glaucous; 

 leaves quite smooth both sides, lanceolate, taper-pointed, very sharply serrate, 

 except the narrowed base, rough-ciliate ; the ample panicle pubescent ; rays 

 7 -14, rather long. (S. gigantea, of previous ed.) Copses and fence-rows; 

 common, and presenting many varieties. Seldom very tall. 



Var. gigantda, Gray. Commonly tall, 5-8 high ; leaves more or less 

 pubescent or hispidulous beneath. (S. gigantea, Ait.; S. serotiua of previous 

 ed.) Thickets and low grounds, Can. to Tex. 



32. S. rupestris, Raf. Stem smooth, slender, 2-3 high; leaves linear- 

 lanceolate, tapering both ways, entire or nearly so ; panicle narrow ; heads very 

 small ; rays 4-6, very short. Rocky river-banks, W. Va. to Ky. and Ind. 



= = Pubescent (at least the stem) or hispidulous-scabrous. 



33. S. Canadensis, L. Stem rough-hairy, tall and stout (3 -6 high); 

 leaves lanceolate, pointed, sharply serrate (sometimes almost entire), more or 

 less pubescent beneath and rough above ; heads small ; rai/s very short. Borders 

 of thickets and fields; very common. Varies greatly in the roughness and 

 hairiness of the stem and leaves, the latter oblong-lanceolate or elongated 

 linear-lanceolate; in var. PR&CERA, whitish-woolly underneath; and in var. 

 SCABRA also very rough above, often entire, and rugose-veined. 



34. S. nemoralis, Ait. Clothed with a minute and close grayish-hoary 

 (soft or roughish) pubescence ; stem simple or corymbed at the summit (i - 2- 

 high) ; leaves oblnnceolate or spat ul ate -oblong, the lower somewhat creuate- 

 toothed and tapering into a petiole ; racemes numerous, dense, at length re- 

 curved, forming a large and crowded compound raceme or panicle 'which is 

 usually turned to one side ; scales of the involucre linear-oblong, appressed ; 

 rays 5-9. Dry sterile fields; very common. Flowers very bright yellow, 

 beginning early in Aug. Var. INC ANA, Gray, of Minn., and westward, is a 

 dwarf form, with rigid oval or oblong leaves, rather strongly serrate or entire, 

 and the clusters of heads in a dense oblong or conical thyrse. 



35. S. radula, Nutt. Stem and oblong or obovate-spatulate leaves rigid 

 and very rough, not hoary, the upper sessile; scales oblong, rigid; rays 3-6; 

 otherwise nearly as in n. 34. Dry hills, W. 111., Minn., Kan., and southward. 



