312 



LXXV. COMPOSITiE. 



^ Pappus capillary. . 



{Scales much imbricated. ( Pappus plumose. . 

 < spreading, petaloid. . 

 Scales in 2 series, . . ( erect, greenish. . 

 Scales in l row or series 



I Receptacle ^ Heads heterogamous. 

 Scales < not chafty. ( Heads dioecious. 



colored. ( Receptacle chaffy 



( Fls. all \ Invol. imbricated. , 

 < equal. < Invol. calyculate. . 

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



unarmed. L Fls. not all perfect, (.green. ^Shrubby. Heads dioecious. 



( Scales acute- ^ Achenia smooth. . . 

 fwithspinose < cuspidate. ..< Acherua rugose, 4-angled. 



j leaves ( Sceiles emarginate-mucronate 



i { Heads homog*mous. 



§ 1. 1 Plants armed. Lvi^ith spinose heads only. I Heads heteroeephalous. . . 



^ Receptacle flat. . 

 * < homogamous. i Receptacle conical. 



^ Heads many, I heterocephalus 



J erect. ( Head solitary, terminal 



< Stem herbaceous, I climbing and twining 



§ 2. { Stem shrubby. Heads monoecious 



^ Heads corymbose. 

 . < erect, l Heads racemose. . 



(f dry, I spreading, petcdoid, yellow. 

 [ ^ green. , . 

 1 i erect, close, I yellowish. 

 ( Corollas < Scales unarmed, I herbaceous, I spreading and loose. . 

 Leaves < all equal. < Scales of the involucre doubly spinose 

 alternate. ( Outer corollas enlarged and sterile 

 S Awns of the achenia re trorsely hispid. . . . 

 Leaves opposite. (Awns of the achenia upwardly hispid. . . ... 



S Heads small, 

 r Involucre ^ Pappus simple. I Hds. verj' large, 

 J imbricated, t Pappus double. Hds. midl. size. 

 flat or 1 Involuc. not \ Outer scales very short or 0. . 

 convex. L imbricated. ( Outer scales equal to the inner. 

 <i Ray flowers pistillate. 

 f Receptacle not chafly, Lconical or globose. . . I Ray flowers neutral. . 

 I ^ Achenia quadrangiuar. 



I ( Pappus minute or 0. ( Achenia compressed. 



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



I < sterile. (Pappus of 2 persistent awns. Achenia winged. 



§ 4. 1 Receptacle chafly. ( Rays fertile. Ach. obcompressed (parallel with the scales) . 



^ Awnas of ach. retrorsely hispid. 

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



(Rays sterile, involucre imbricate in 3 or more rows. .... 

 5 Adhenia obovoid, thick. 

 ( disk sterile. . . 

 < 

 Rays fertile, ( disk perfect. . . 



f Achenia obcompressed, winged, 

 S Receptacle nearly flat. . 

 l Receptacle conical. . 

 <, Scales 5, united in 1 row. 

 Sc. in 2 rows, outer row distinct. 



V pinnate 

 1 S Lvs. opposite, I undi\ided. Scales distinct. 



§ 5. 1 Recept. not chafly. ( Leaves radical, appearing after the solitarj' head. . . 



\ Rays white, shorter than scales. 

 < Receptacle flat. ( Rays rose color. .... 

 J simple. I Receptacle conical, with large palese. • 

 ( Leaves opposite, i pinnately divided. Inner invol. of 8 united scales. 



\ \ Heads coiymbose " . • 



§ 6. ( Leaves all rtidical I Head solitar>', heteroeamous 



^ Achenia silky. Rays about 5. . 

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

 I simple, i of 2 short bri.stles and several minute ones. 

 I ^ Heads middle size. 



{alveolate. I Pappus double. < Heads verj' larse. 

 ( Pappus capillary. Invol. subsimple. Rays 20—200. 

 \ S Involucre depressed, broad, 



smoothish. ( Pappus none. . . I Involucre hemispherical. . 



< Rays pistillate. 

 < Disk fls. yellow, i Rays neutral. 

 fLvs. finely dlAided. ^ Disk fls. white. Rays pistillate. .. 

 I 1 3 or 4. . 



I 5 Rays very short, white, (5. . .. 



§7. 1 Receptacle chafly. (.Leaves undivided. { Rays very large, purple. . 



^ in 2—3 rows. 

 ^ Scales of the invol. equal. ( in 1 row. 

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



'Lvs. radical, (Flowers white; pappus plumose 



5 Pappus single, bristly. 

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

 C Fls. yellow. ( Lvs. spinose-dentate ; pappus very white 



CAchenia< Flowers blue. Pappus small, scaly 



I not rost. ( Fls. whitish or cream color. Pap. copious, capillary, 

 ■j ( with a fill- ^ Involucre with calyculate scales. . 



Achenia < form beak. { Involucre without calyculate scales. 

 § 8, l.Lv8. cauline. Lrostrate. ( with a short, thick beak ; involucre imbricate. . 



