232 COMPOSITE. (COMPOSITE FAillLY.) 



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-leaved 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 apprtssed and 



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



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



17. A. ericoides, L. Smuotk or sparingly liairy (l°-l£° high) ; the sim- 

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

 spreading branches ; lowest leaves oblong-spatulate, sometimes toothed ; the ot/iers 

 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. 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. multifidrus, 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 chiate mar- 

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

 volucre with spatulate spreading green tips broader than the 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. dumdsus, L. Smooth or nearly so, racemosely compound, the 

 scattered heads 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 Unear-spatulate, 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. Euns into several peculiar forms. 



20. A. TradeSCanti, L. Smooth or smoothish ; the 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 acufish, 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. More or less hairy, 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 middh ■• 



