234 cu-Mrosn\i:. (composite family.) 



■i- ■*- Leaves opposite, serrate. Disk-flowers yellow. 



60. Galinsoga. Rays few, short, pistillate, whitish. Involucre of 4-5 thin ovate scales. 



Receptacle chaffj'. 



Tribe VI. HELENIOIDE^. Nearly as Ti-ibe V., but receptacle not chaffy (some- 

 what so in n . 64). In our genera, the disk-flowers perfect and fertile ; the pappus a row 

 of several chaffy scales (bristly-dissected in n. 65) ; the involucre hardly at all imbricated 

 (partly scarious in n. 61). 



* Involucral scales distinct, not glandular-punctate. 



61. Hymenopappus. Rays none. Receptacle flat. Involucre colored. Western. 



62. Actinella. Rays fertile, 3-toothed. Receptacle elevated. Involucre appressed. Western. 

 63 Heleniuin. Rays fertile or sterile, 3- 5-cleft. Receptacle elevated. Involucre small, 



reflexed. Leaves decurrent. 

 61. Gaillardia. Ray 3-toothed, or none. Receptacle usually beset with fine finibrillate 

 chaff. Outer involucral scales loose and leafy. Pappus-chaff tipped with the pro- 

 jecting midvein. Western. 



« * Dotted with oil-glands. Inv(jlucral scales united into a cup. 



65. Dysodia. Pappus a row of chaffy scales dissected into many bristles. 



Tribe VII. ANTHEMIDE.^]. Distinguished from the last two tribes by the more or 

 less dry and scarious imbricated scales of the involucre. Heads radiate (ray mostly 

 white) or discoid, the pei-fect flowers sometimes sterile and the pistillate rarely tubu- 

 lar. Achenes small ; pappus a short crown or none. — Mostly strong-scented ; leaves 

 alternate. 



* Receptacle chaffy, at least in part. Heads radiate, many-flowered. 



66. Anthemis. Achenes terete, angled or ribbed. Heads hemisplierical, rather large. 



67. Achillea. Achenes obcompressed. Heads small, campanula te or obovate. 



* * Receptacle naked. 

 -(- Heads raUier large, pedunculate, radiate or rarely rayless. 



68. Matricaria. Receptacle conical. Rays pistillate or none. Pappus crown-like or none. 



69. Clirysaiitliemum. Receptacle flattish. Rays many, pistillate. Pappus none. 



-t- -*- Heads mostly small, discoid, corymbed or paniculate. 



70 Tanacetuni. Heads corymbed. Achene with broad summit ; pappus a short crown. 



71. Artemisia. Heads in panicled spikes or racemes. Achenes with narrow summit; 



pappus none. 



Tribe VIII. SENECIONIDE^. Heads radiate or discoid, the involucre little or 

 not at all imbricated, not scarious. Receptacle naked. Anthers tailless. Pappus 

 capillary. 



* Heads monoecious or subdicecious, the perfect flowers mostly sterile, and the small (ligu- 



late or tubular) ray-flowers in more than one row (at least in the fertile heads). Style- 

 branches obtuse, not appendaged nor hispid. Leaves all radical. 



72. Tussilago. Head solitary, yellow-flowered, monoecious. 



73. Petasites. Heads corymbed, subdicecious. Flowers white or purplish. 



* » Flowers all fertile. Style-branches truncate or capitellate, often appendaged. Involu- 



cral scales connivent-erect. 



■*- Leaves opposite. 



74. Arnica. Heads showy. Pappus rather rigid, scabrous. 



•(- -t- Leaves alternate. Pappus soft-capillary, copious, 



75. Senecio. Heads usually radiate. Corollas yellow, 5-toothed. 



76. Cacalia. Heads discoid. Corollas white or cream-colored, 5-cleft. 



77. Erechtites. Heads discoid. Flowers whitish, the outer pistillate with filiform corollas. 



