MICHIGAN ACADEMY OF SCIENCE. 
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h. Basal leaves 7-12 cm. long, more or less crenate- 
serrate above the middle; tliyrse rarely branched. 
(sand hills) 8. raccrnosa 
hh. Basal leaves 15-30 cm. long, coarsely and sharply 
serrate the entire length; tliyrse panicnlately 
branched, (sand hills and rocks along shore of Lake 
Michigan) 8. racemosci , v. GiUmannii 
gg. Heads on pedicels not over 5 mm. long; achenes glab- 
rous or nearly so; stems usually solitary, 
h. Leaves pinnately veined, (swamps) . . . .8. uliginosa 
hh. Leaves 3-5 ribbed, (swamps) 8. neglecta 
ee. Racemes or branches of the panicle usually elongated, 
spreading outwards, usually recurved, forming a widened 
panicle (pyramidal type), 
f. Both sides of the leaves pubescent or scabrous. 
g. Stem and both sides of the leaves covered with a 
close, hoary, soft pubescence, (dry, sandy soil) 
8. nemoralis 
gg. Stem glabrous throughout ; leaves more or less scab- 
rous on both sides, (dry or rocky soil) 
8. juncea , v. scabrella 
ff. Both sides of the leaves not pubescent or scabrous. 
g. Leaves very rough above, very smooth beneath ; stem 
strongly angled, (swamps and bogs) 8. patula 
gg. Leaves smooth both sides ; stem terete. 
h. Branches of the panicle spreading, recurved, 
secuud. with heads the whole length, (dry or rocky 
soil) 8. juncea 
hh. Branches of the panicle upright, hardly recurved, 
only slightly second, with heads in short, terminal 
racemes, (dry or rocky soil) . .8. juncea , r. ramosa 
Leaves essentially uniform from base to summit of stem, 
e. Stem more or less pubescent or hairy throughout. 
f. Involucre 2-2.8 mm. long, (thickets and rich, open fields; 
roadsides) 8. canadensis 
ff. Involucre 3-5 mm. long. 
g. Leaves pinnately veined, scabrous above, rather long- 
hairy beneath; more or less rugose-veined, (dry soil, 
or sometimes on borders of marshes) 
8. rugosa 
gg. Leaves 3-5-ribbed, pubescent (but not scabrous) above, 
short-hairy beneath; not rugose-veined, 
h. Stem and lower surface of leaves short-pilose; 
racemes strongly recurved, (rich, open ground) . . 
*8. altissima 
hh. Stem and lower surface of leaves hairy with dis- 
tinct. loose, soft hairs; racemes scarcely recurved, 
(shores of Lake Superior) . . 8. altissima, r. proccra 
ee. Stem glabrous, at least below 1 he inflorescence. 
f. Involucre 2-2.8 mm. long (thickets and rich, open fields, 
roadsides) 8. canadensis 
