34() 



COMPOSITAE. 



forming the involucre; heads 1-many, discoid when all the flowers 

 bear tubular corollas, ligtdate when the corollas are all strap- 

 shaped, radiate when the outer corollas are strap-shaped and 

 the inner tubular, in which case the outer are ray-flowers and 

 the inner disk-flowers; receptacle often covered with bracts or 

 scales (chaff), each subtending a flower; calyx gamosepalous, its 

 tube wholly adherent to the ovary, its limb (pappus) none or 

 cup-shaped or developed into teeth, scales, awns or capillary 

 bristles; corollas alike in all the flowers of the head or dissimilar, 

 either tubular or strap-shaped (ligulate), gamopetalous, epigy- 

 nous; stamens 5, epipetalous, their anthers usually united into a 

 tube (syngenesious); style 2-cleft at the apex or in sterile flowers 

 usually entire; ovary bicarpellary, inferior, 1-celled, 1-ovuled, 

 with basal placenta; fruit an akene, sometimes surmounted by 

 the pappus, often compressed at right angles to the subtending 

 chaff {laterally compressed) or compressed parallel to the chaff 

 {ohcom pressed) . 



SYNOPSIS OF THE TRIBES. 



Corollas strap-shaped in all the flowers of the head; 



plants with milky juice. 

 Corollas tubular in all the flowers of the head or 

 strap-shaped in only the marginal ones; 

 plants without milky juice. 

 Stamens distinct or nearly so. 

 Stamens united by their anthers into a tube 

 around the style (syngenesious). 

 Anthers caudate at base; style-branches 

 neither truncate nor appendaged; 

 heads not radiate. 

 Receptacle not bristly; corollas not 



deeply cleft. 

 Receptacle long bristly; corollas deeply 

 cleft. 



Anthers not caudate at base; style branches 

 either truncate or tipped with an ap- 

 pendage. 

 Heads rayless; style branches club- 

 shaped, obtuse; flowers all perfect, 

 never yellow. 

 Heads radiate (rarely rayless). 



Style branches of perfect flowers flat, 

 or tipped with a distinct append- 

 age; leaves mostly alternate. 

 Style branches of perfect flowers 

 truncate or appendaged, not 

 flattened; leaves often opposite. 

 Involucre scarious; pappus not 

 capillary. 



Tribe i. Cichorieae. 



Tribe 2. Ambrosieae. 



Tribe 9. 

 Tribe 10. 



Inuleae. 

 Cyn.\re.\e. 



Tribe 3. Eupatorieae. 



Tribe 4. Astereae. 



Tribe 7. Anthemideae. 



