compositje. (composite family.) 193 



underneath, lanceolate or ovate-lanceolate, elongated, tapering gradually to a sharp 

 point, all but the uppermost more or less heart-shaped at the base and on naked peti- 

 oles ; involucre bell-shaped. — Cliffs and banks, Ohio to Wisconsin and south- 

 ward. — A pretty species, 2°-4° high; the leaves 3'-5' long. 



13. A, unclulatiis, L. Pale or somewhat hoary with close pubescence ; 

 stem spreading, bearing numerous heads in racemose panicles ; leaves ovate or 

 ovate-lanceolate, with warn/ or slightly toothed margins, roughish above, downy under- 

 neath, the lowest heart-shaped on margined petioles, the others abruptly contracted 

 into sliort broadly winged petioles which are dilated and clasping at the base, or direct- 

 ly sessile by a heart-shaped base; involucre obovoid. (A. diversif61ius, Michx.) 

 — Dry copses, common. 



t- -t- Leaves conspicuously serrate : heads small : rays pale blue or nearly white. 



14. A. cordifolius, L. Stem much branched above, the spreading or 

 diverging branches bearing very numerous panicled heads ; lower leaves all heart- 

 shaped, on slender and mostly naked ciliate petioles ; scales of the inversely coni- 

 cal involucre all appressed and tipped with short green points, obtuse or acutish. — 

 Woodlands ; very common. Varies with the stem and leaves either smooth, 

 roughish, or sometimes hairy underneath. Heads produced in great profusion, 

 but quite small. 



15. A. sag^ittifolius, Willd. Stem rigid, er&ct, with ascending branches 

 bearing numerous racemose heads; leaves ovate-lanceolate, pointed; the lower 

 heart-shaped at the base, on margined petioles ; the upper lanceolate or linear, 

 pointed at both ends ; scales of the oblong involucre linear, tapering into awl-sliaped 

 slender and loose tips. — Dry ground. New York and Penn. to Wisconsin and 

 Kentucky. — Usually more or less haiiy or downy; the heads rather larger 

 than in the last, almost sessile. — A. Drummondii, Lindl., which probably 

 grows on the Illinois side of the Mississippi, is apparently only a downy-lewed 

 variety of this. 



* # * # Leaves none of them heart-shaped; those of the stem sessile, narrow, rigid, 

 entire : involucre imbricated in several rows : the coriaceous scales appressed and 

 whitish at the base, with abrupt and conspicuous spreading herbaceous tips : heads 

 small and very numerous, paniculate-racemose : rays ivhite. 



16. A. eriCOMleS, L. Smooth or sparingly hairy (1°-14° high); the 

 simple branchlets or peduncles racemose along the upper side of the wand-like 

 spreading branches ; lowest leaves oblong-spatulate, sometimes toothed ; the others 

 linear-lanceolate or linear-awl-shaped, acute at both ends ; scales of the involucre 

 broadest at the base, with acute or awl-shaped green tips. — Var. vii,l6sus is a 

 hairy form, often with broader leaves ; chiefly in the Western States. — Dry 

 open places, S. New England to Wisconsin and southward. 



17. A« multifloms, Ait. Pale or Iioary with minute close pubescence (1° 

 high), much branched and bushy; the heads much crowded on the spreading 

 racemose branches ; leaves crowded, linear, spreading, with rough or ciliate mar- 

 gins, tke upper somewhat dilated and partly clasping at the base ; scales of the invo- 

 lucre with spatulate spreading green tips broadur than the lower portion, the outer 

 obtuse. — Dry gravelly or sandy soil; common. » flioo-': 



17 



