COMPOSITE. (COMPOSITE FAMILY.) 261 



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

 or acutisli, in 3 or 4 rows. (A. Tradescauti, of previous eel.) Var. FOLIO- 

 Ldsus, Gray, has linear entire leaves, the ascending branches with more scat- 

 tered paniculate heads. Moist banks ; very common. Heads very numerous, 

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



35. A. diffllSUS, Ait. More or /ess pubescent, mucli branched ; leaves 

 lanceolate or oblong-laiiceolate, tapering or pointed at each end, sharply ser- 

 rate in the middle; scales of the involucre linear, acute or rather obtuse, imbri- 

 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. THYRSO- 

 fDEUs, Gray, with ovate-oblong to lanceolate le.i\cs, the branches ascending 

 and often short, and the thyrsoid or spicatc-;;-lomerate heads less secund. 

 N. Y. to 111. Var. HiRSUTiCAfjLis, Gray, the slender stem and the midveins 

 of the long narrow leaves very hirsute. N. Y. and Ky. Var. BI'FRONS, Gray, 

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

 posed ou the spreading branches. Ky. to 111. 



+- -t- - - Incolucre 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 

 ofn. 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. pauiculatus 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 whollv green. (A. simplex, 

 previous ed.) Shady moist banks; common. Ravs 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 rarelv 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 scalea 

 often obtuse. 111. to Tex. 



