<x 



232 COMPOSITE. (composite family.) 



pointed at both ends ; scales of the oblong involucre linear, tapering into aid-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 oppressed 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. Smooth or sparingly hairy (1° - 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 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. 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. mu.ltifl.6rus, 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 somewltat 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 slwii. and narrow op- 

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

 bluish-purple. 



h- 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 linear-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. Rays pale 

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



20. A. Tradesc&nti, L. Smooth or smoothish ; the numerous heads closely 

 raremed 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. frag i lis 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 stuttered heads; leaves lanceolate or ob- 

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



