ORDER 70. COMPOSITE. 155 



Scales distinct. Cypselfe 4-angled. Pappus HELIOPSIS. 51 



Cypsehe flattened. Pappus : SPILANTHES. 60 



Cypselfe flat, with a 2-awned pappus VERBKSIXA. Cl 



t .Leaves alternate. Pappus none. Adienia terete AXTHEMIS. 7<J 



( Leaves alternate. Pappus none. Achenia obcompressed ACHILLEA. 71 



t Leaves opposite. Pappus n me ECLTPTA. 37 



Pappus of fringed scales GALINSOGA. 38 



Pappus of the disk a single awn, of the ray ZINNIA. 50 



K Leaves opposite. Kays yellow. Pappus none POLY.MNIA. 39 



Leaves opposite. Rays yellow. Pappus a 2- or 3-toothed crown. Gen. 11, & CHRYSOGO.NUM. 10 



v Leaves alternate. Kays whitish, very short, 5 only PARTHENIUM. 45 



Rays yellow, disk dark-purple. Leaves entire MADIA. 43 



Rays yellow, disk brown. Leaves cut SPHEXOGYNE. 44 



Rays and disk yellow. Fruit winged SILPIIIUM. 41 



Fruit wingless BF.RLANDIERA. 12 



c Cypsela with erectly hispid awns, or awnless, never rostrate COREOPSIS. 58 



e Cypsela with retrorsely hispid awns, often attenuated above. BIDENS. 59 



x Bays white, spreading. Pappus none ANTHEMIIS. 70 



x Bays purple, pendent. Pales sharp, elongated ECHIXACEA. 53 



c Bays yellow. Pappus none. Cypsela quadrangular RUDBECKIA. 54 



Pappus none. Cypsela compressed LKP ACHIS. 55 



Pappus of 2 awns. Fruit wingless HELIANTHUS. 56 



Fruit broad-winged ACTIXOMERIS. 57 



B. SUBORDER LIGULIFLOR^E. 



g Papps none, or consisting of little scales... (a) 

 g$ Pappus double (of scales and bristles), or simple and plumous...(ft) 

 Pappus composed of capillary bristles, not plumous...(*) 

 * Achenia terete or angular, not flattened... (c) 

 Achenia evidently flattened. ..(-f) 



a Flowers yellow. Pappus none. Heads paniculate LAMPSANA. 99 



a Flowers yellow. Pappus none. Heads solitary or umbellate APOGON. 100 



a Flowers blue. Pappus of many little scales. Receptacle naked CICHORIUM. 101 



Pappus of 5 scales. Receptacle chaffy C ATANANCHE. 107 



b Flowers purple. Feathery pappus on a long filiform beak TRAGOPOGOX. 105 



b Flowers yellow. Feathery pappus on a short beak or sessile LEONTODOX. 101 



b Flowers yellow. Pappus of many bristles with the scales CYNTHIA. 103 



Pappus of 5 bristles and 5 scales KRIGIA. 102 



c Flowers whitish or purplish, mostly nodding. Stem leafy NABALUS. 108 



r Flowers rose-purple, erect. (Stem almost leafless) LYGODERMIA. 109 



c Flowers yellow. Achenia long-beaked. Pappus white TARAXACUM. 112 



Achenia long-beaked. Pappus reddish PYRROPAPPUS. Ill 



Achenia not beaked. Pappus dull-white or tawny HIERACIUM. 106 



Pappus bright white TKOSIMON. 1 10 



d Achenia contracted into a slender beak. Flowers mostly yellow LACTUCA. 113 



d Achenia scarcely beaked. Flowers mostly blue MULGEDIUM. 114 



Flowers yellow. Pappus silky SONCHUS. 115 



C. SUBORDER LABIATIFLOILE. 



3g Head radiate, solitary, nodding in bud. Pappus capillary CHAPTALIA. 117 



1 VERNONIA, Schreb. IRON WEED. Fls. all tubular, perfect. In. 



vol. of ovate, imbricated scales, the inner longest. Recept. naked. Pap. 



double, the exterior chaffy, the interior capillary. U 5 Leaves alternate, 



Fls. purple (in our species). Cymes corymbed. Figs. 446-8. 



Scales of the involucre all obtuse and closely appressed. Stem tall, grooved. ..No. 1 



Scales of the in vol. (usually all) a with slender, flexuous points Nos. 2, 3 



a with acute or mucronatc points. South. . .Nos. 1-6 



