238 THE FLORA.. 



§ Disk with its corollas and pales dark purple a 



§ Disk with its corollas and pales yellow c 



a Herbs annual. Leaves chiefly alternate 1, 2 



a Herbs perennial. Leaves opposite b 



b Scales of the involucre acuminate 3-5 



b Scales of the involucre obtuse 6, 7 



c Leaves chiefly alternate and feather-veined 8-11 



c Leaves chiefly opposite and 3-veined or triple- veined. . ..d 



d Scales of involucre erect, closely imbricated e 



d Scales loosely spreading. Heads large, 9-15-rayed f 



d Scales loosely spreading. Heads small, 5-8-rayed.... 22-25 



e Plants green, rough 12, 13 



e Plants whitish, downy 14, 15 



f Scales lance-linea.r, longer than disk. Leaves thin ... .16, 17 

 f Scales lance-ovate, as long as the disk. Leaves thick 18-21 



1 H. an'nuus. Common. S. Stout and tall (3-lOf.). Heads large 6-10 across, 



nodding. Achenia (seeds) glabrous. A variety has all the flowers ligulate. 



2 H. deb'ilis. Slender S. Slender, decumbent. Heads small. Seeds downy. S. 



3 H. Rad'ula. Basp-h\ S. Leaves roundish, rough, obtuse. Kays 7-10 or none. S. 



4 H. heterophyrius. Leaves oval, lanceolate, &c. Kays 12-18. Pales acute. S. 



5 H. angustifo'lius. Leaves lance-linear, pointed. Pales 3-toothed. N.-J. S. 



6 H. rigidus. Eigid S. Lvs. lanceolate, pointed. Scales ovate, acute. Ks. 12-20. W. 



7 H. atrorubens. Livid S. Leaves ovate, obtusish. Scales oblong, obtuse. S. 



8 H. gigan'teus. Tall S. Hairy, rough. Lvs. lanceolate, pointed, serrate, e. 



9 H. tomento'sus. Velvets. Very downy. Lower lvs. ovate, nearly entire. W. S. 



10 H. grosse-serra'tus. Coarse-toothed S. Stem smooth. Leaves lance-pointed, 



sharp-serrate. Kays 15-20. W. 



11 H. tubero'sus. Artichoke. Cultiv. Lvs. 3-veined, lower cordate-ovate. 



12 H. lEEtiflo'rus. Laughing S. Branched. Leaves lance-oval, short petioled. 



13 H. occidema'Us. Western S. Stem slender, simple, nearly leafless above. 



14 H. mol'Us. Srft S. Leaves ovate, cordate, sessile. Plant woolly. W. 



15 H. cine'reus. Ashy S. Lvs. ovate-oblong, tapering to base. Ashy-downy. O. 



16 H. decapet'alous. Ten-rayed S. Kays 9-12. Leaves all opposite. Stem 3-4f. N. M. 



17 H. tracheliifo'Uus. Trach-leaved S. Kays 12-15. Branch lvs. alternate. 4-8f. W. 



18 H. doronicoi'des. False Tiger-bane. Leaves petiolate, ovate, and lance- 



ovate, upper alternate. Scales longer than disk. Kays 12-15. W. S. 



19 H. strumo'sus. Warty S. Leaves short-petioled, lance-ovate, all alike. 



Scales equalling the disk. c. A double-flowered variety is cultivated. 



20 H. hirsu'tus. Hairy S. Leaves petiolate, hairy beneath. Scales hairy. W. 



21 H. divarica'tus. Forked S. Leaves sessile, very rough, opposite or ternate. c. 



22 H. microceph'alus. Small S. Stem smooth, much branched. Lvs. narrow. W. 



23 H. Schweinit'zii. Schweinitz' s S. Stem downy, rough. Leaves white, downy. Car. 



24 H. Iseviga'tus. Polished S. Stem and leaves very smooth. Not branched. S. Mts. 



25 H. longifo'lius. Long-led. S. Leaves lanee-linear, acute, smooth. Kays 8-10. Ga 



