COMrOSITE FAMILY. 237 



•1- -1- Scales varionshi imbricated, the tips herbaceous (r/reen) ami spread- 

 ing, or the outer ones lohulhj leaf-like. 



** Leaves silvery-silky both sides, and sessile and entire. 



A. serlceus, Vent. Slender, l°-2° ; leaves lanceolate or oblong, 

 spreadin.t; ; involucre globular with spreading scales; heads mostly soli- 

 tary, sliowy, violet. Dry soil. Wis., W. and S. 



A. c6ncolor, Linn. Leaves crowrded and appressed, as are the scales 

 of the obovoid involucre ; heads in a compound wand-like raceme, violet. 

 Near the coast, H. L, S. 



-w ++ Leaves not silvery-silky, various. 



= Stem leaves all {or at lea.'^t the lowest) cordate and j^etioled ; radical 

 leaves all prominently cordate. 



II Bays about 40 ; involucral scales sqnarrose. 



A. an6malus, Engelm. I'ubescent and roughish, 2"-4° ; upper leaves 

 small and nearly or quite sessile ; heads rather large, bright violet. IlL, 

 W. and S. 



II II Hays 10-20, light-blue or irhite ; scales not sqnarrose. 



o All ur part of the petioles icing-margined. 



A. unduleltus, Linn. Leaves ovate or lance-ovate, the margins wavy 

 or sliiilitly tuothed, roughish above and downy beneath, the uppermost 

 with olasi)inL,'' pftioles. Common. 



A. sagittif61ius, Wiild. Rigid and erect, 2°-'S°, with ascending 

 branches ; leavis ovate-lanceolate, the lower cordate and on margined 

 petioles, the uppjr becoming narrower ; involucre obU)ng, the scales 

 narrow-taperhig and loose. Common, N. and S. 



o o Petioles not wing-margined {except occasionally in the first). 



A. cordif6lius, Linn. Stem much branched, the branches diverging 

 and bearing very numerous panicled heads ; lower stem leaves all pro- 

 minently heart-shaped, the petioles ciliate and only slightly or not at all 

 margined ; involucre obconical, with short and nearly obtuse, appressed 

 tips. Common, Can. to Ga., and W. Variable. 



A. azilreus, Lindl. Heads larger ; leaves ovate-lanceolate or oblong, 

 rough, the petioles usually long and hairy, the uppermost becoming 

 nearly linear and sessile, or on the branches even awl-like ; involucre 

 obconical, slightly pubescent. N. Y., S. and W. 



= = Stem leaves clasping or sessile {or if short-stalked, not cordate), 

 vai'ious. 



o Leaves broadish, prominently cordate-clasping or with a vnnged- 

 petiole-like base. ( Forms of A. Xovi-Belgii and A. oblongifoUus, 

 below, may be sought here.) 



X Leaves entire {rarely very obscurely toothed in first two). 



A. l^vis, Linn. Smooth and glabrous, often glaucous, 2°-4° ; leaves 

 thickish, lanceolate or broader, the upper auricnlatc, or cordate, clasp- 

 ing ; involucre hemispherical, with abrupt green tips; rays blue. Com- 

 mon and handsome. 



A. patens, Ait. Rough-pubescent, l°-3°, the branches loose and 

 widely si)reading ; leaves ovate-oblong or longer, rough above and on the 

 margins ; involucre ovoid, scales with pointed spreading tips ; rays purple. 

 N. and S. 



A. N6vce-AngliaB, Linn. Tall and stout, .3°-8", hairy, very leafy ; 

 leaves lauciMilate and acute, pubescent; scales nearly equal and loose,, 

 awl-like, glandular-viscid ; flowers large, rose or purple. Can. to S. C, 

 anil W. ; also cult. 



