256 COMPOSITE. (composite family.) 



* * Disk convex, yellow : scales of the involucre regularly imbricated and oppressed, 

 with somewhat spreading and acute (but not foliaceous) tips : leaves chiefly opposite. 



5. H. lsetifldrus, Pers. Stout an d rough (3° -4° high), branching above; 

 leaves oval-lanceolate, very rough both sides, narrowed into short petioles, serrate, taper- 

 pointed, the uppermost alternate and nearly entire ; heads single or corymbed, 

 on naked peduncles ; scales of the involucre ovate-lanceolate, pointed, ciliate. — 

 Dry open places, Ohio to Illinois, and southward. — Leaves almost as thick as 

 in H. rigidus. Rays showy, 1 ' - 2' long. 



6. H. OCCident&lis, Riddell. Somewhat hairy ; stem slender, simple, naked 

 above (l°-3° high, sending out runners from the base), bearing 1-5 small 

 heads on long peduncles ; lowest leaves oval or lanceolate-ovate, 3-nerved, obscurely 

 serrate, roughish-pubescent beneath, abruptly contracted into long hairy petioles; the 

 upper small and remote, entire ; scales of the involucre oval-lanceolate, pointed, 

 ciliate. — Dry barrens, Ohio to Wisconsin, Kentucky, and southward. 



7. H. cinereus, var. Sullivantii, Torr. & Gr. Gray ivith a close rough- 

 ish pubescence ; stem branching above, hairy ; leaves ovate-oblong, sessile by a nar- 

 rowed base, acute, obscurely serrate ; the upper small and remote ; peduncles 

 slender ; scales of the involucre lanceolate, hoary. — Darby Plains, Ohio, Sulli- 

 vant. Stem 2° - 3° high, bearing few heads, as large as those of the next. 



8. H. mollis, Lam. Stem clothed with soft white hairs, simple, leafy, to 

 the top (2° -4° high) ; leaves ovate, with a broad heart-shaped and clasping base, 

 pointed, nearly entire, hoary above, very soft white-woolly and reticulated under- 

 neath ; scales of the involucre lanceolate, downy. — Barrens and Prairies, Ohio 

 to Illinois, and westward. 



* * * Heads very small (about 4" broad) : scales of the involucre few, shorter than the 



yellow disk, irregularly imbricated, oppressed, the outer with spreading foliaceous 

 pointed tips : rays 5-8, slender : leaves all but the uppermost opposite. 



9. H. microc6phalus, Torr. & Gr. Stem smooth (3° -8° high), with 

 numerous slender branches above ; leaves thin, ovate-lanceolate, taper-pointed, 

 somewhat serrate, veiny, petioled, rough above, downy or hairy underneath ; pe- 

 duncles slender, rough ; scales of the involucre ovate and ovate-lanceolate, 

 ciliate. — Thickets, Pennsylvania to Illinois, and southward. 



10. H. laevigatas, Torr. & Gr. Stem slender (l°-4° high), simple or 

 sparingly branched, very smooth and glabrous throughout, as well as the slightly 

 serrate lanceolate leaves.— Dry soil, Alleghany Mountains, west of the Warm 

 Springs of Virginia, and southward. 



* * * * Heads middle-sized or large : scales of the involucre irregularly imbricated, 



loose, with spreading foliaceous tips, as long as the yellow disk or longer. 

 ■*- Leaves chiefly alternate or scattered, feather-veined, sometimes obscurely triple-ribbed. 



11. H. giganteUS, L. Stem hairy or rough (3° -10° high), branched 

 above ; leaves lanceolate, pointed, serrate, very rough above, rough-hairy beneath, 

 narrowed and ciliate at the base, but nearly sessile ; scales of the involucre long, 

 linear-lanceolate, pointed, hairy, or strongly ciliate. — Var. ambiguus has most 

 of the leaves opposite and closely sessile by an obtuse base, and approaches No. 

 14. — Low thickets and swamps : common. Heads somewhat corymbed: the 

 pale yellow rays 15-20. 



