ORDER 70. COMPOSITE. 155 



Scales distinct. Cj-pselae 4-angled. Pappus HELIOPSIS. 51 



Cypselae flattened. Pappus 0. ... : SPILANTHES. 60 



Cypselae flat, with a 2-awned pappus VERBESINA. 61 



* Leaves alternate. Pappus none. Achenia terete ANTHEMIS. 70 



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



t Leave? opposite. Pappus nine ECLIPTA. 37 



Pappus of fringed scales GALINSOGA. 38 



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



u Leaves opposite. Rays yelloiv. Pappus none POLYMNIA. J9 



u Leaves opposite. Rays yellow. Pappus a 2- or 3-toothed crown. Gen. 41, & CIIRYSOGONCM. 10 



u Leaves alternate. Rays whitish, very short, 5 only PARTHEXIUM. 45 



Rays yellow, disk dark-purple. Leaves entire MADIA. 4!{ 



Rays yellow, disk brown. Leaves cut SPHEXOGYNE. 41 



Rays and disk yellow. Fruit winged SILPHIU.U. 4 1 



Fruit wingless BERLANDIERA. 12 



r Cypsela with erectly hispid awns, or awnless, never rostrate COREOPSIS. 53 



v Cypsela with retrorsely hispid awns, often attenuated above EIDENS. 59 



x Rays white, spreading. Pappus none AXTHKMIIS. 70. 



x Rays purple, pendent. Pales sharp, elongated ECHINACEA. 53 



t Rays yellow. Pappus none. Cypsela quadrangular RUDBECKIA. 54 



Pappus none. Cypsela compressed LEPACHIS. 55 



Pappus of 2 awns. Fruit wingless HELIANTUUS. 56 



Fruit broad-winged ACTIXOMERIS. 57 



B. SUBORDER LIGULIFLOR^E. 



$$ Pappus none, or consisting of little scales. . .(a) 

 |$ Pappus double (of scales and bristles), or simple and plumous...(7>) 

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

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

 A.chenia evidently flattened. . .(,1) 



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



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



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



Pappus of 5 scales. Receptacle chaffy CATAN AXCHK. 107 



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



l> Flowers yellow. Feathery pappus on a short beak or sessile LEOXTODOX. 104 



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 NABALCS. 108 



r Flowers rose-purple, erect. (Stem almost leafless) LYGODESMIA. 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 TROXIMON. 110 



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



d Achenia scarcely beaked. Flowers mostly blue MULGEDICM. 114 



Flowers yellow. Pappus silky SOXCHUS. 115 



C. SUBORDER LABIATIFLOR.E. 



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 invol. (usually all) a with slender, flesuous points Nos. 2, 3 



a with acute or mucronatc points. South. . .Nos. 4-6 



