334 COMPOSITE 



43 Halianthns Achines thick, quadrangular-compressed or with the 

 sides convex and the angles obtuse : pappus a pair of. caducous ceaffy 

 scales or awns, 



SuBTRiBE IV, BiDENTiE^a; Heads radiate, the rays neutral or 

 pistillate. Receptacle chaffy with flat or barely concave decidu- 

 ous chaff. Achines all obcompressed. Pappus of 2-4 teeth or 

 awns from the angles, or none. 



44 Coreopsis Achenes never rostrate-attenuate nor with retroaely barb- 

 ed awns. 



45 Bldens Achenes neither winged nor beaked, 2-5-awned with retrorse- 

 ly barbed persistent awns. 



SuBTRiBE V, Galinsoge^s: Heads heterogamous with the ray- 

 flowers, when present, fertile; disk-flowers either perfect and 

 fertile or sterile. Achenes neither compressed nor obcompressed 

 Pappus in both ray and disk- flowers few to numerous chaffy 

 scales. 



46 Blepharipappns Heads radiate ; the rays pistillate : pappus of 12-20 



thin scales with a stout midrib. 



SuBTEiBE VI, Madieje Hcads heterogamous ; ray-flowers, when 

 present, fertile ; disk flowers either perfect and fertile, pr sterile. 

 Involucre a series of bracts, each subtending and more or less en- 

 closing a ray-achene. Receptacle chafiy only at the margin, the^ 

 chaff forming a sort of inner involucre or else subtending some or 

 all of the disk flowers. 



* Achenes all laterally compressed ; those of the ray wholly enclosed 

 in the carinate strongly Infolding bracts of the involucre. 



47 Anisoearpns Kays conspicuous and mostly numerous, fertile ; disk- 

 flowers numerous, sterile or the exterior ones fertile ; with pubescent 

 corolla and a pappus composed of fimbriate or plumose-lacerate scales. 



48 Madaria Bays numerous and conspicuous : disk-flowers without pap- 



pus, either all or only the central ones sterile. 



40 Madia Bays 1-12 or none, short and more or less inconspicuous disk- 

 flowers numerous or few, all fertile, destitute of pappus. 



50 Harpiecarpns Bays 4-8 very short and inconspicuous ; disk-flower 

 solitary, fertile, eAclosed in a 3-5-toothed heibaceous cup: pappus none. 



* * Achenes of the ray-flowers turgid, moJe or less obliqe or incurv- 

 ed, never latterally com'pressed but mostly somewhat obcompressed: 

 bracts of the involucre each investing an achene, rounded on the back. 



51 Hemizonella Involucre strongly 4-5-sulcate by the complete enwrap- 

 ing of the 4 or 5 achenes : disk-flower solitaryin a sort of inner invo- 

 lucre : pappus none. 



52 Hemlzonla Achenes of the ray-flowers obovate-triangular, with de- 

 pressed terminal areola ; disk-flowers numerous, with abortive achenes: 

 pappus none. 



68 Caiycadenia Achenes of the ray-flowers obovoid, the terminal areola 

 little if at all oblique, triangular | of the numerous disk-flowers well 

 formed, and sometimes truly fertile, surrounded by a circle of herba- 

 ceou bracts ; pappus of conspicuous chaffy scales. 



