COMPOSITiE. (composite FAMILY.) 261 



the middle with fine sharp teeth; scales a/the involucre narrowly linear, acute 

 or acuds/i, in 3 or 4 rows. (A. Tradescauti, of previous ed.) — Var. Foi.io- 

 l6sl'S, Gray, has linear entire leaves, the ascending branches with more scat- 

 tered paniculate lieads. — Moist banks ; very common. — Heads very numerous, 

 and usually crowded, smaller than in the last. Rays white or nearly so. 



3.5. A. difiusUS, Ait. More or less pubescent, much branched ; leaves 

 lanceolate or oblong-lauceolate, tapering or pointed at each end, sharplij ser- 

 rate in the mtddle ; scales of the involucre linear, acute or rather obtuse, unhri- 

 cated in 3 or 4 rows. (A. miser, of previous ed.) — Thickets, fields, etc.; 

 very common, and extensively variable. Leaves larger than in either of the 

 preceding (2-5') ; the involucre intermediate between them, as to the form of 

 the scales. Rays mostly short, white or pale bluish-purple. — Var. THVRSo- 

 fDEUs, Gray, with ovate-oblong to lanceolate leaves, tiie branches ascending 

 and often short, and the thyrsoid or spicate-glomerate heads less secund. 

 N. Y. to 111. — Var. iiiRSUTiCAt'Lis, Gray, the slender stem and the midveins 

 of the long narrow leaves very hirsute. X. Y. and Ky. — A'ar. p.ifkoxs. Gray, 

 a luxuriant form with large thin leaves and rather larger heads loosely dis- 

 posed on the spreading branches. Ky. to 111. 



-t- -1- -t- -1- Involucre various, the heads when numerous densely or loosely panic- 

 ulate on erect or ascending branches. 



*+ Cauline leaves sessile, but the base not cordate nor auriculate {except in forms 

 ofu. 41 ), nor winged-petiole-like ; glabrous or nearly so. 



== Heads small or middle-sized : scales narrow, in several lengths, the erect green 



tips not dilated. 



36. A. Tradescanti, L. Stem much branched (2-4° high); the nu- 

 merous heads (2-3" high) somewhat panicled or racemed ; leaves lanceolate 

 to linear, tapering to a long slender point (2-6' long), the lower somewhat 

 serrate in the middle ; involucral scales linear, acutish, partly green down the 

 back. (A. tenuifolius, previous ed.) — Low grounds, Mass. to Minn., and south 

 to Va. and 111. Rays short and narrow, white or purplish. Some forms ap- 

 proach n. 32-34, others differ from A. paniculatus only in the smaller heads 

 and shorter ray. 



37. A. paniculatus, Lam. Stem (2 - 8° high) much branched ; the 

 branches and scattered heads (about 4" high) loosely paniculate; leaves long- 

 oblong to narrowly lanceolate, pointed, the lower serrate ; scales narrowly 

 linear, with attenuate green tips or the outermost wholly green. (A. simplex, 

 previous ed.) — Shady moist banks ; common. Rays white or purplish, 3 - 4" 

 long. Approaches in its different forms the preceding and the two following. 

 A slender form with linear leaves, in northern bogs, resembles n. 40. 



38. A. salicifolius, Ait. Like the last ; the leaves commonly shorter, 

 firmer, often scabrous, less serrate or entire; involucre more imbricated, the 

 firmer linear scales with shorter acute or obtusish green tips ; heads as large, 

 disposed to be thyrsoid or racemose-clustered ; rays rarely white. (A. carneus, 

 previous ed. ) — Low grounds, N. Eng. to Minn., and southward ; most abundant 

 westward. — Var. subasper, Gray, a rigid scabrous form, with contracted leafy 

 inflorescence, the broad heads usually leafy-bracteate and the broader scales 

 often o])tuse. 111. to Tex. 



