313 



LXXV. COMPOSITiE. 



^ Pappus capillary. . Vemonia. l 



{Scales much imbricated. (Pappus plumose. . Liatris. 7 

 ( spreading, petaloid. . Hijmenopapptts. 50 

 Scales in 2 series, . . I erect, greenish. . . Eiephantopus. 2 

 Scales in 1 row or series. . . . . . Cacalia. 51 



4 Receptacle ^ Heads heterogamous. Gnapha/ium. 54 



r Scales < not chatty. ( Heads dia?cious. . Antennaria. 55 



colored. ( Receptacle chatiy FUago. 



Plants 

 unarmed. L 



iFls 

 < equal. 



Pluchea. 



Erechtites. 



Centaurea. 



Baccharia. 



Cirsium. 



Onopordon. 



Cynara. 



Lappa. 



Xanthium. 



Eupatorium. 



( Invol. imbricated. 

 , v-.i..«.. ( Invol. calyculate. 



Scales <, Herbs. ( Ray flowers larger, sterile. 

 Fls. not all perfect. I green. ^Shrubby. Heads dioGcious. 



i( Scales acute- \ Achenia smooth. . . 

 with spinose < cuspidate. . . I Achenia rugose, 4-angled. 

 leaves ( Scales emarffinate-mucronate. . 

 { Head.s homog«mous. 

 with spinose heads ojily. ( Heads heterdcephalous. . . 

 \ Receptacle flat. 

 (, homo?amous. ( Receptacle conical. Conoclimum. 



J Heads many, I heteriicephalus Ambrosia. 



\ erect. I Head solitary, terminal Sclerolepis. 



^ Stem herbaceous, l climbing and twining Mikania. 



§ 2. i Stem shrubby. Heads monoecious. . . . • • • • • • i^°- 



< Heads corymbose. 



{k erect. \ Heads racemose. . 

 dry, \ spreading, petaloid, yellow. 

 \ green. . 

 S erect, close, \ yellowish, 

 herbaceous, ( spreading and loose. . 



Leaves ^ all equal. ^Scales of the involucre doubly spniose 



alternate. ( Outer corollas enlarged and sterile Amberboa. 



J Awns ofthe achenia re trorsely hispid Bidens. 



Leaves opposite, i Awns of the achenia upwardly hispid. . ■„• • „• Coreopsis. 



\ Heads small. Sohdago. 

 r Involucre i Pappus simple. ( Hds.verj' large. J»?/Zffi. _ 

 J imbricated. \ Pappus double. Hds. midl. size. Chrysopsis. 

 fflat or I Involuc. not \ Outer scales very short or 0. . Senecio. 

 j convex. L imbricated. I Outer scales equal to the inner. Calendula. 



Tanacetum. 



Artemisia. 



Xeranthemtwi. 



Senecio. 



Bigelovia. 



Cdrthamus. 



Cnicus. 



( Receptacle not chafly, (. conical or globose. 



Ray flowers pistillate. . . Helenium. 

 Ray flowers neutral. . . Leptopoda. 

 \ Achenia quadrangular. . Rttdbeckia. 

 Pappus minute or 0. t Achenia compressed. . Lepachys. 

 (Rays < Pappus of 2 caducous awns. Achenia wingless. Hehanthm. 

 I ■' sterile. ( Pappus of 2 persistent awns. Achenia winged. Actinomeris. 



§ 4. I Receptacle chafiy. i Rays fertile. Ach. obcompressed (parallel with the scaJes). Silphtimi. 



\ Awns of ach. retrorsely hispid. Bidens. 

 < Involucre double. ( Awns of ach. erectly hispid. . Coreopsis. 

 fRays sterile, involucre imbricate in 3 or more rows. . . . Hehanthm. 



J Achenia obovoid, thick. . . Polymma. 

 { (■ disk sterile. .. . (Achenia obcompressed, winged. SjVp/zmw, 



C Receptacle . 



chaffy. . . I Rays fertile, ( disk perfect. 



Verbesina. 

 Heliopsis. 

 Tagetes. 



^ Receptacle nearly flat. 

 \ Receptacle conical. . 

 \ Scales 5, united in 1 row 



1 ^pinnate. ( Sc. in 2 rows, outerrow distinct. Dysodia. 



^Lvs. opposite, (undivided. Scales distinct. . . . Arnica. 



§ 5. iRecept. notchaflTy. (Leaves radical, appearing afler the solitary head. . . Tusnlago. 



^ Rays white, shorter than scales. Eclipta. 



4 Receptacle flat. ( Rays rose color Coreopsis. 



^simple. (Receptacle conical, with large paleifi. . . . Zinnia. 



( Leaves opposite, (pinnatelv di\'i(led. Inner invol. of 8 united scales. . . DaJiHa. 



{ ( Heads corjmbose iSardosmia. 



§ 6. ( Leaves all radical ( Head soliUry, hefcroiramous. . . . . . Belhs. 



^ Achenia silky. Rays about 5. . Sericocarpvs. 

 r Pappus (copious. ( Achenia smoothish. Rays 6— 100. Aster. 

 J simple, (of 2 short bristles and several minute ones 

 i Heads middle size 



('alveolate. 



Receptacle ] 



not chafl"y, (.smoothish. 



Boltonia. 



Diplopapptis. 



CaUistephus. 



Erigeron. 



Leiicanthemum. 



I Pappus double. I Heads very large. 



' Pappus capillar}'. Invol. subsimple. Rays 20- 



( Involucre depressed, broad. 



Pappus none. . . ( Involucre hemispherical. . 



( Rays pistillate 



( Disk fls. yellow, i Rays neutral. 



■ Lvs. finely di\aded. I Disk fls. white. Rays pistillate. 



1 3 or 4. 

 J Rays very short, white, ( 5. 

 § 7. I Receptacle chafiy. I Leaves undivided. ( Rays very large, purple. . . . Ecfiinacea. 



(in 2— 3 rows. . Troxnnon. 

 C Seniles of the invol. equal. ( in 1 row. . . Krigia. 

 ( Flowers yellow. ( Outer scales shortest, pappus capillary. . . Taraxinim. 



■ Lvs. radical. ( Flowers white ; pappus plumose : , • Leontodon. 



j Pappus single, bnstly. Hieracmm. 

 ( Lvs. unarmed. (Pap. double, outer scaly. Cynthia. 

 ( Fls. yellow. ( Lvs. spitiose-dentate ; pappus very white. Son cfnis. 



1Achenia< Flowers blue. Pappus small, scaly. . . • • CicJwrium. 

 not rost. f Fls. whitish or cream color. Pap. copious, capillarj-. ^abalits. 

 i with a fill- ( Involucre with calyculate sciiJes. . . Lactnca. 

 Achenia -J form beak. ( Involucre without calyculate .scales. . Tragopogon 

 rostrate. ( with a short, thick beak ; involucre imbricate. . . Mulgedmm. 



Chrysanthemum.iZ 



Anthemis. 37 



Maruta. 38 



Achillea. 39 



Verbesina. 47 



Parthenimn. 28 



31 



81 



72 



82 



74 



79 



73 



