COMPOSITAE (COMPOSITE FAMILY) 



479 



A WHS not retrorsely barbed or hispid, often at length 



deciduous. 



Ray-flowers fertile; achenes winged . . .55. Ximenegia. 

 Ray-flowers neutral. 



Involucral bracts distinct, somewhat foliaceous 54. Helianthella. 

 Involucral bracts all more or less united at base 56. Coreopsis. 

 Awns retrorsely barbed or hispid. 



Involucral bracts united only at base . . . 57. Bidens. 

 Involucral bracts united into a cup . . . 58. Thelesperma. 

 Involucral bracts partly or wholly inclosing the ray achenes. 



Rays 1-5, inconspicuous, yellow ..... 59. Madia. 



Rays 8-12, conspicuous, white or rose ..... 60. Layia. 



Tribe VI. HELENIEAE 



Herbage without oil-glands; not rank-scented but often aromatic. 

 Ligules persistent and becoming papery; plants more or less 



woolly 61. Psilostrophe. 



Ligules deciduous or wanting. 



Achenes flat, with only marginal nerves 62. Pericome. 



Achenes angled (not flat), nerved or striate. 

 Receptacle not chaffy. 



At least the tips of the involucral bracts petaloid or scar- 

 ious. 



Heads rayless 63. Hymenopappus. 



Heads radiate. 



Ligules white or yellowish ..... 64. Leucampyz. 



Ligules purple 65. Polypteris. 



Involucral bracts not petaloid or scarious. 

 Achenes 4-angled. 



Leaves all entire 67. Platyschkuhria. 



Leaves not all entire. 



Bracts of the involucre in 2 series, more or less 



united . 66. Eriophyllun. 



Bracts of the involucre distinct. 

 Plants not glutinous or viscid. 



Flowers yellow 68. Bahia. 



Flowers white or flesh-color .... 69. Chaenactis. 



Plants glutinous or viscid . . . .70. Hulsea. 



Achenes 5-10-ribbed; herbage commonly impressed- 



punctate and resiniferous. 

 Pappus present. 



Involucral bracts erect. 



Leaves entire, usually linear . . . .71. Actinella. 



Leaves not entire. 



Herbage glabrous or becoming glabrate . 72. Hymenoxys. 



Low woolly alpine perennial, with enormous 



heads . . .... 73. Rydbergia. 



Involucral bracts spreading or reflexed. 



Leaves not decurrent on the stem, usually some 



of them parted 74. Dugaldea. 



Leaves decurrent on the stem, entire . . 75. Helenium. 



Pappus wanting 76. Flaveria. 



Receptacle with bristle-like chaff 77. Gaillardia. 



Herbage with oil-glands, heavy or rank scented. 



Leaves pinnately divided ........ 78. Dysqdia. 



Leaves entire, narrow 79. Pectis. 



Tribe VH. ANTHEMIDEAE 



Receptacle chaffy, at least in part. 



Heads broad; rays conspicuous ...... 80. Anthemis. 



Heads narrow; rays short 81. Achillea. 



Receptacle naked. 



Heads solitary or corymbose. 



Receptacle conical, at least in age ..... 



Receptacle flattish or only moderately convex. 



Heads radiate ......... 



Heads rayless 



Heads several to many, spicate or racemose-paniculate, discoid 



Tribe Vm. SENECIONEAE 



Flowers white or purple; rays wanting 86. Petasites. 



Flowers yellow. 

 Leaves opposite. 



Involucral bracts spreading 87. Haploesthes. 



Involucral bracts erect or connivent ..... 88. Arnica. 

 Leaves alternate. 



Shrubs; heads rayless, 4-9-flowered 89. Tetradymia. 



Herbs; rays usually present, flowers many . . . .90. Senecio. 



82. Matricaria. 



83. Chrysanthemum. 



84. Tanacetum. 



85. Artemisia. 



