1154 



CAKDUACEAE 



ft Corolla merely funnelform : involucre broadly campanulate. 

 ** Heads with both disk- and ray-flowers, with individual excep- 

 tions. 



Pappus-bristles as long as the achene or longer, at least those 

 of the ray : leaf-blades narrow or narrowed at the base, or 

 if truncate or subcordate, narrowed into a broad petiole- 

 like base. 



Leaf-blades bristly serrate, pinnatifid or pinnately-parted. 

 Achenes glabrous : pappus-bristles deciduous. 

 Achenes pubescent : pappus-bristles persistent. 

 Corolla-tube slender, scarcely dilated above. 

 Corolla-tube markedly dilated above. 

 Leaf-blades entire or merely toothed, the teeth not bristle- 

 tipped. 

 Annual or biennial plants. 



Pappus-bristles nearly equal : ray-flowers with soft 



curled ligules. 

 Pappus-bristles very unequal : ray-flowers with firm 



involute ligules. 

 Perennial plants. 



Bracts of the involucre broad, longitudinally ribbed. 

 Ligules of the ray-flowers elongated-linear : disk- 

 corollas with a cylindrical throat. 

 Ligules of the ray-flowers shorter than the tube : 



disk-corollas with a campanulate throat. 

 Bracts of the involucre narrow, not ribbed. 

 Plants woody at the base, or undershrubs. 



Corolla-tube markedly dilated : leaves with even 



surfaces. 

 Corolla-tube scarcely dilated: leaves with rounded 



or angular depressions. 

 Plants wholly herbaceous. 



Receptacle pubescent, fimbrillate : ray-flowers 



more numerous than those of the disk. 

 Receptacle alveolate: ray-flowers fewer than 



those of the disk. 



Pappus-bristles shorter than the achene : leaf-blades, at least 

 those of the basal and lower cauline leaves, cordate, nar- 

 rowed into slender petioles, 

 b. Ray-flowers with white or colored corollas but not yellow. 



Pappus a mere crown or of few awns, scales or awn-like bristles, or 



wanting. 



Receptacle conic or strongly convex. 

 Pappus wanting or obsolete. 

 Pappus present. 



Pappus an entire, toothed or ciliate crown. 



Pappus of short bristles with a pair of awns over each edge of 



the achene. 



Bracts of the involucre essentially equal : pappus of several 

 minute scales hidden in the hairs of the achene, in 

 addition to the awns. 

 Bracts of the involucre very unequal : pappus of several 



longer scales in addition to the awns. 

 Receptacle flat, rarely with a central appendage. 

 Pappus a minute crown, sometimes evanescent. 

 Pappus of scales, awns or bristles. 



Pappus of scales alternating with awns, or these wanting. 

 Heads 3-few-flowered : involucre turbinate. 



Heads discoid, sessile: pappus of lanceolate scales: 



bracts of the involucre appendaged at the tip. 

 Heads radiate, peduncled : pappus of scales and awns : 



bracts of the involucre un append aged. 

 Heads many-flowered : involucre hemispheric to campanu- 

 late. 



Pappus of rigid bristles, that of the ray sometimes scale-like. 

 Pappus, at least in the disk, of numerous capillary bristles. 

 Pappus of the ray-flowers a mere vestige or obsolete. 

 Pappus of the ray and disk essentially similar. 

 Pappus-bristles in a single series or mainly so. 

 Bracts of the involucre in 3-many series. 

 Bracts in 3-5 series. 



Ray-flowers few ; ligules relatively short and broad : 



bracts of the involucre leathery. 



Ray-flowers numerous ; ligules relatively long and nar- 

 row : bracts of the involucre mainly herbaceous. 

 Bracts in many series. 

 Bracts of the involucre in 1 or 2 series. 



Ray-flowers with ligules longer than the diameter of the disk. 

 Ray-flowers with ligules shorter than the diameter of the 



disk. 



Pappus-bristles manifestly in 2 series. 

 Stigma-tips obtuse. 

 Stigma-tips acute or acuminate. 



Involucre of 2-4 series of bracts, the inner bracts not much 

 surpassing the achenes : ray-flowers with white ligules. 

 Involucre of 5-6 series of bract?, the inner bracts much sur- 

 passing the achenes : ray-flowers with violet ligules. 

 B. Ray-flowers wanting : plants dioecious. 



28. BRINTONIA. 



29. PRIONOPSIS. 



30. SlDERANTHUS. 



31. ISOCOMA. 



32. ISOPAPPUS. 



33. MAUCHIA. 



34. STANFIELDIA. 



35. OLIGONEURON. 



31. ISOCOMA. 



36. CHRYSOMA. 



37. EUTHAMIA. 



38. SOLIDAGO. 



39. BRACHYCHAETA. 



40. BELLIS. 



41. APHANOSTEPHUS. 



42. DlCHAETOPHORA. 



43. BOLTONIA. 



44. KEERLIA. 



45. THUROVIA. 



46. CHAETOPAPPA. 



47. DISTASIS. 



48. TOWNSENDIA. 



49. PSILACTIS. 



50. SERICOCARPUS. 



51. ASTER. 



52. MACHAERANTHERA. 



53. ERIGERON. 



54. LEPTILON. 

 53. ERIGERON. 



55. DOELLINGERIA. 



56. lONAOTIS. 



57. BACCHARIS. 



