ASTEKACKAi: 



y. Pappus 



| x I Re< ■ ptai le smooth 

 Receptai le chaffj 

 (b) Leaves not strong s< ented 

 \. Pappus a crown, or none 

 y. Pappus oi two or more barbed awm 

 2. Flowers of two kinds, tubular and ray, 01 ..II raj 



a. Ilea. Is with chaff, i. e., each Bower with a 



(1) Ray flowers trumpet-shaped 



(2) Kay flowers flat, ribbon- or strap sfa 



(a) Kays white 



\. I .. aves pinnately dissec ted, strong • 

 y. Leaves not dissei ted or strong - • 



(b) Rays yelloM or purple 

 x. 1 >isk globose to cylii 



(x) Chafl stoul or spiny; rays white, red oi ; . 

 in. Chaff equalling the disk flowers 

 ii. Chaff much longer than the disk ll. i 

 (y) < l,.iM -..ii ; raj - yellow 

 in. 1 lisk globose ; a< hem - -1 angled 

 n. Disk oblong to cylindric; achenes wing marj 

 y. I »isk Hat or slightly 



(x) Bracts of the involucre united, at leasl 

 in. Chafl broad; achenes flat, winged-marg 

 ii. ( 'hall' linear or long pointed : a. henes not i! il 

 (m) Kays white to pink or red 

 (n) Rays yellow to maroon 

 r. Pappus teeth barbed upward or downward 

 s. Pappus teeth smooth or lacking 

 (y) Bracts not united, or somewhat so at 

 m. Achenes broad, winded 



(m) Rays in 2-3 rows; disk flow 

 (n) Kays in 1 row; disk flowers fi 

 n. Achenes not winged 



(m) Kays neutral, deciduous 

 r. Pappus of t\\<> triangular awns; 

 s. Pappus of two awns and small - 

 (n) Kays pistillate, persistent; pappus crown-like 



b. Heads without chaff ; the receptacle slightly bi 



(1) Pappus of capillarj bristles 

 (a) Rays yellow 



\. I leads small, 2 8 mm. 

 Heads larger, 1-3 cm. 



Kays white to blue or purple 

 x. I leads single, on shorl 



y. I leads several many 



(x) Kays narrow an., many; br... !- in 1 i r< 

 i y i Kays broader and ewer; bri 

 m. Pappus double ; i ultivati d annual 

 n. Pappus single ; native 

 i m I Heads in a 



I leads in a i j on 



(2) Pappus none, or of ; 12 

 (a) Pappus 



\. .\. disk small ai 



(b) 



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