232 compositjE. (composite family.) 



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



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



northward. — Usually more or less hairy 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 a downy-leav«d variety of this. 



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



entire : involucre imbricated in several rows : ike coriaceous scales oppressed and 



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



small and very numerous, paniculate-racemose ; rays white. 



17. A. erieoides, L. Smooth or sparingly liairy (1°-1§° high) ; the sim- 

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

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

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

 broadest at the base, with acute or awl-sluiped green lips, — Var. vill6sus is a 

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

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



18. A. multiflbrUS, Ait. Pale or hoary 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, the upper somewhat dilated and partly clasping at the base ; scales of the in- 

 volucre with spalulate spreading green tips broader than tlie lower portion, the outer 

 obtuse. — Dry gravelly or sandy soil ; common. 



***** Leaves none of them heart-shaped; those of the stem tapering at the base, 

 sessile; involucre imbricated; the scales unequal, with short and narrow op- 

 pressed or rather loose greenish tips : heads small or middle-sized : rays white or 

 bluish-purple. 



■*- Heads small. {Involucre 2"-4" long.) 



19. A. duiIl6sU6, L. Smooth or nearly so, racemosely compound, the 

 scattered lieads mostly solitary at the end of the spreading branchlets ; leaves linear 

 Or the upper oblong, crowded, entire or slightly serrate, with rough margins ; 

 scales of the closely imbricated involucre linear-spatuhite, obtuse, in 4 - 6 rows. — 

 Thickets: common. — A variable species, l°-3°high, loosely branched, with 

 small leaves, especially the upper, and an inversely conical or bell-shaped invo- 

 lucre, with more abrupt green tips than any of the succeeding. Eays pale 

 purple or blue, larger than in the next. Runs into several peculiar forms. 



20. A. Tradese&nti, L. Smooth or smoothish ; tie numerous heads closely 

 racemed along one side of the erect-spreading or diverging branches ; leaves 

 lanceolate-linear, elongated, the larger ones remotely serrate in the middle with 

 fine sharp teeth ; scales of the involucre narrowly linear, acute or acutish, in .3 or 4 

 rows. — Var. frAgilis has the leaves entire or nearly so, except the lowest, 

 the heads more scattered. — Moist banks : very common. — Stems 2° - 4° 

 high, bushy : heads very numerous, smaller than in the last. Rays white or 

 nearly so. 



21. A. miser,)L., Ait. Jl/ore or fes Amry, much branched ; the branches 

 usually diverging, bearing racemose often scattered heads ; leaves lanceolate or ob- 

 long-lanceolate, tapering or pointed at each end, sharply serrate in the middle ; 



