OEDEB LXIV. COMPOSITE COMPOSITE-FAMILY. 



165 



cylindrical, with the linear, green scales in a single row. Pappus abundant, 

 white, very soft 



GROUP 4. 

 Central flowers perfect ; marginal mostly enlarged and sterile. 



40. CENTAUBEA. Receptacle bristly. Pappus composed of capillary, rough 

 bristles, in several rows. 



41. AMIIKKHOA. Pappus consisting of oblong, or obovate, chaffy scales; 

 rarely small or none, 



GROUP 5. 



Heads consisting wholly of either Staminate or pistillate flowers (rareiy in 

 Antennaria a fuw Muminate flowers in the centre of the pistillate beads). 



84. ANTENNARIA. Plants with dioecious flowers. Receptacle somewhat 

 convex, alveolate. Woolly herbs. 



:i6. XANTHIUM. Plants with monoecious flowers. Staminate in short * e r- 

 ininat racemes ; pistillate ones in small clusters, at the base of the Staminate. 

 Fertile heads 2-tlowered, covered with hooked prickles, forming a burr. Pappus 

 none. 



87. AMBROSIA. Flowers monoecious. Sterile flowers nodding, in long ra- 

 cemes. Fertile flowers in a closed, 1-flowered involucre, axillary, near the 

 base of the sterile raceme. 



&. Lower leaves at least opposite or verticiUate. 



GROUP. 6. 

 Central and marginal flowers perfect 



2. EUPATORIUM. Heads 3 many-flowered. Involucre-scales 8 or more. 

 Pappus simple, capillary. Receptacle naked. Erect herbs. 



3. MIKANIA. Heads 4-flowered. Involucre-scales 4. Receptacle naked. 

 Pappus simple, capihary. Climbing herbs. 



29. BIDENS. Heads many-flowered. Receptacle chaffy. Pappus consisting 

 of 2 i, stiff, barbed awns. 



GROUP 7. 



Central flowers Staminate ; marginal ones pistillate, fertile. 



88. IVA. Heads small, on short recurved peduncles, racemose, forming 

 leafy panicles. Shrubby at base. 



B. Central flowers tubular ; marginal or ray flowers ligulate. 

 a. Leaves all alternate or radical. 



GROUP 8. 

 Rays yellow, pistillate. Disk-flowers perfect 



13. SOLIDAGO. Heads small. Rays about 5, short Involucre-scales imbri- 

 cate. Receptacle flattish, alveolate. 



14. INULA. Heads very large. Rays very numerous. Involucre-scales 

 imbricate. Receptacle flat 



21. HELENIUM. Rays numerous, 3 5-cleft at summit Involucre of re- 

 flexed scales. Receptacle subglobose, naked. 



80. SE.NECIO. Heads in flat corymbs. Involucre-scales in a single row. 

 Rays entire. Receptacle flat 



GROUP 9. 

 Rays not yellow, pistillate. Disk-flowers perfect 



* Receptacle alveolate. 



6. ASTER. Heads corymbose or paniculate. Pappus simple, capillary. 

 Achenia compressed, smooth. 



7. SERICOOARPUS. Heads corymbose. Pappus simple, capillary. Achenia 

 obconic, densely silky. 



8. DIPLOPAPPITS. Heads rather large, corymbose, or solitary. Involucre 

 sonles appressed. Pappus double ; outer series very short; inner of capillary 

 bristles. 



10. CALLisTEpnus. Heads very large, solitary on the branchlets. Involucre 

 scales with large, leafy, spreading tips. Pappus double ; outer series of short 

 chaffy scales; inner series of long capillary, deciduous bristles. 



13. SOLIDAGO. Heads small, in axillary racemes. Rays few, short Pap- 

 pus simple, capillary. 



* * Receptacle naked. 



9. ER!GBRON. Ray flowers very numerous and narrow. Pappus simple or 

 double. Receptacle flat. 



11. BELLIB. Leaves all radical Heads solitary. Receptacle conical. Pap- 

 pus none. 



25. LBUCANTHEMUM. Involucre broad, depressed at the centre. Pappus 

 none. 



26. PTRETHRUM. Involucre hemispherical. Pappus reduced to a mem- 

 branous border or crown. 



27. CHRYSANTHEMUM. Involucre hemispherical. Pappus none. 



* * * Receptacle cltaf f jr. 



22. AKTHEMIS. Rays numerous. Receptacle convex. Pappus reduced to 

 a slight border, crowning the achenia. 



24. ACIULLEA. Rays 510. Receptacle flat Pappus none. 



GROUP 10. 

 Rays neutral. Disk flowers perfect 



23. MAR^TA. Receptacle conical, more or less chafly. Rays white. 



17. RUDBECKIA. Involucre-scales in 2 series. Receptacle conical, chaffy. 

 Pappus none, or a mere border. Rays yellow. 



GROUP 11. 



Rays pistillate. Disk-flowers Staminate. 

 B. TUSSILAGO. Acaulescent Rays very narrow, in many rows. 



89. CALENDULA. Involucre-scales nearly equal, in 2 rows. Pappus none. 

 b. Lower leaves, at least, opposite. 



GROUP 12. 



Rays pistillate. Disk-flowers perfect 



12. DAHLIA. Involucre-scales in 2 rows. Receptacle chaffy. Pappus 

 none. Leaves pinnate. 



16. HELIOPSIS. Involucre-scales imbricated in several rows. Receptacle 

 chaffv, conical. Pappus none. 



18. ZINNIA. Involucre-scales imbricated in several rows. Receptacle 

 chaffy, conical. Pappus of the disk consisting of 2 erect awns. Leaves entire. 



20. TAGETES. Involucre-scales in 1 row. Receptacle naked. Pappus of 5 

 erect awns. Leaves pinnately-parted. 



GROUP 18. 

 Rays neutral. Disk-flowers perfect. 



19. HELIANTIIUS. Involucre-scales in several rows. Receptacle with per- 

 sistent chaff. Pappus persistent, of 2 deciduous, chaffy awns. 



28. COKKOPSIS. Involucre-scales in 2 series. Receptacle with deciduous 

 chaff. Acbenia compressed. Pappus reduced to 2 teeth, or none. 



29. BIDENS. Involucre-scales in 2 series. Receptacle chaffy. Pappus con- 

 sisting of 2 4 barbed awns. Achenia quadrangular. 



SUBORDER II. LignlifldrsD. 



Flowers all ligulate. 



GROUP 1. 

 Plants acaulesccnt. 



48. KR'IOIA. Involucre-scales equal, in 2 rows. Achenia turbinate. Pap- 

 pus double ; outer series of broad scales ; inner of slender bristles. 



49. LKONTODON. Involucre-scales imbricate ; outer ones very short Pap- 

 pus plumose ; bristles in a single series. Achenia scarcely beaked. 



55. TARAXACUM. Involucre-scales in 2 series; inner series appressed ; outer 

 reflexed. Achenia v^ith a long beak, bearing a capillary, copious pappus. 



GROUP 2. 



Plants caulescent Heads yellow. 



63. HIERACIUM. Achenia oblong, not beaked. Pappus-bristles tawny, ca- 

 pillary, in a single series. Leaves toothed or entire. 



51. LACTUCA. Achenia compressed, with a long filiform beak. Pappus 

 verv abundant white and soft 



56. 86NCHUS. Achenia compressed, not beaked. Pappus very abundant 

 white, soft, capillary. 



GROUP 8. 



Plants caulescent. Heads not yellow. 



47. CiciidRiuM. Involucre-scales in 2 series. Pappus of very short scales. 

 Achenia not beaked. Leaves runcinate. 



50. TRAGOPOGON. Involucre-scales in a single series. Achenia with a long, 

 filiform beak. Pappus plumose. Leaves linear. 



52. MULOEDIUM. Involucre-scales in 2 series ; outer ones short Achenia 

 flattish, with short thick beaks. Pappus soft, capillary. 



54. NABALOS. Involucre-scales cylindric, in a single row, with a few ap- 

 pressed bractleta at base, Achenia not beaked. Heads mostly in axillary 

 racemes. 



1. VERNtiNIA. 



Heads 15 many-flowered. Involucre of many ovate, ap- 

 pressed, imbricated scales, shorter than the flowers. Receptacle 

 naked. Achenia cylindrical, ribbed. Pappus double ; the outer 

 short, chafly ; the inner capillary. Per. 



1. V. Noveboracensis. Iron-weed. 



Stem erect branching above ; leaves alternate, lanceolate, serrulate, pubes- 

 cent underneath ; heads rather large, dark purple, in terminal, compound, flat- 

 topped cymes ; scales of the involucre terminating in a long awn, or bristle- 

 like appendage. A tall plant 4 6 feet high, in swamps, with numerous dark 

 purple beads. Quite showy. Aug. Sep. 



2. ETTPAT6RIUM. 



Heads 3 many-flowered. Involucre cylindrical, imbricate, 

 Receptacle flat. Style much exsert. Pappus simple, roughish. 

 Achenia 5-angled. Per. 



1. E. purpiireum. Trumpet-weed. 



Stem tall, simple; leaves varying from broad-ovate to lanceolate, acuminate, 

 veiny, somewhat rough, serrate or toothed, 8 6 in a whorl ; heads 5 10-flow- 

 ered; scales of the involucre purplish, numerous, closely imbricated in several 

 rows of unequal length ; flowers light purple, in dense compound corymbs. An 

 exceedingly variable plant The stem ranges from 210 feet high, is solid or 

 hollow, spotted or without spots, and sometimes dotted ; leaves also variable in 

 shape and size. Low ground. Very common. Aug.^Sep. 



2. E. teucrifolium. 



Pubescent and somewhat rough ; leaves opposite, ovate or ovate-lanceolate, 

 obtuse at base, sessile, veiny ; upper ones alternate and nearly entire ; heads in 

 corymbs, with a few unequal branches, about 8-flowered, white ; scales about 



