774 COMPOSITAE (CO^IPOSITE FAMILY) 



scales (bristly -dissected in no. 66); the involucre hardly at all imbricated (partly scarious in 



no. 61). 



* Involucral bracts distinct, not glandular-punctate. 



-f- Pappus none ; bracts 2-5, carinate. 



60. Flaveria. Heads small. Ray single or none. 



+■ +- Pappus of distinct scales or bristles or wanting ; bracts more than 5. 

 •H- Tips of bracts colored or petaloid. 



61. Hymenopappus. Lower leaves pinnatifid. Rays none. Disk-flowers with ovate lobes. 



62. Polypteris. Leaves undivided. Rays generally none. Disk-flowers with hnear lobes. 



-H- ++ Tips of bracts not colored and petaloid. 



63. Actlnea. Rays fertile, 3-toothed. Receptacle elevated. Involucral bracts appressed. 



64. Helenium. Rays fertile or sterile, 3-5-cleft. Receptacle elevated. Involucre small, reflexed. 



Leaves decurrent. 



65. Gaillardia. Rays 3-toothed, or none. Receptacle usually beset with fine fimbrillate chaff. 



Outer involucral bracts loose and leafy. Pappus-chalF tipped with the projecting mid- 

 vein. "Western. 



* * Dotted with oil-glands ; involucral bracts united into a cup. 



66. Dyssodia. Pappus a row of chaffy scales dissected into many bristles. 



Tribe VII. ANTHEMIdEAE. Distinguished from the last two tribes by the more or less dry 

 and scarious imbricated bracts of the involucre. Heads radiate (rays mostly white) or discoid, 

 the perfect flowers sometimes sterile and the pistillate rarely tubular. Achenes small ; pappus 

 a short crown or none. Mostly strong-scented ; leaves alternate. 



* Receptacle chafly, at least in part ; heads radiate, many-flowered. 



67. Achillea. Receptacle flattish. Achenes obcompressed. Heads small, campanulate or obovoid. 



68. AnthemiS. Achenes subterete, angled or ribbed. Heads hemispherical, rather large. 



* * Receptacle naked. 



+- Heads solitary or corymbose. 



++ Receptacle conical at least in age. 



69. Matricaria. Heads pedunculate. Rays pistillate or none. Pappus crown-like or none. 



Leaves finely dissected. 



-H- ++ Receptacle flattish or moderately convex. 



= Corollas of the perfect flowers 5-toothed ; achenes sessile. 



70. Chrysanthemum. Heads radiate (or rayless in one variety with leaves almost or quite 



unlobed); rays pistillate. Achenes 5-10-nerved ; pappus none. 



71. Tanacetum. Heads discoid. Pistillate flowers few, marginal, their corollas inconspicuous, 



2-3-toothed. Achenes 3-5-angled ; pappus none or a short crown. 



= = Corollas of the perfect flowers 4-toothed ; achenes stalked. 



72. Cotula. Heads long-peduncled, discoid. Pistillate flowers destitute of corolla. Achenes 



raised upon papillae which persist upon the receptacle. 



+- +- Inflorescence from spike-like to chiefly racemose-paniculate. 



73. Artemisia. Heads small, usually drooping, discoid. Pappus none. 



Tribe VIII. SENECI6nEAE. Heads radiate or discoid, <he involucre little or not at all imbricated, 

 not scarious. Receptacle naked. Anthers tailless. Pappus capillary. 



* Heads monoecious or subdioecious, the perfect flowers mostly sterile, and the small (ligulate or 

 tubular) ray-flowers in more than one row (at least in the fertile heads) ; style-branches 

 obtuse, not appendaged nor hispid ; leaves chiefly radical. 



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



75. Petasites. Heads corymbed, subdioecious. Flowers white or purpUsh. 



••= * Flowers all fertile ; style-branches truncate or capitellate, often appendaged ; involucral bracts 



connivent-erect. 

 -I- Leaves opposite. 



76. Arnica Heads showy. Pappus rather rigid, scabrous or barbellate. 



