COMPOSITE.. (composite FAMILY.) 



185 



Achenia not ribbed, 5-angled. No. 



Receptacle conical CONOCLINIUM. 14 



Keceptacle flat. Stems climbing. MIKANIA. 13 



Receptacle flat. Stems erect EUPATORIUM. 12 



Pappus scaly. 

 Flowers blue or purple. 



Pappus a cup-shaped border of united scales COELESTINA. 5 



Pappus slender, almost bristly. 



Pappus deciduous. Heads large and single STOKESIA. 2 



Pappus persistent. Heads small, in 3-bracted clusters. . ELEPHANTOPUS. 3 



Pappus of 5 oval almost bony scales. Leaves whorled. . . SCLEROLEPIS. 7 

 Flowers white. 

 Receptacle naked. 



Leaves entire, linear or lanceolate PALAFOXIA. 5" 



Leaves entire, ovate or cordate AGERATUM. 6 



Leaves pinnately lobed IIYMENOPAPPUS. 58 



Receptacle chaffy. 



Achenium top-shaped. Scales of the pappus 5 - 6. . . . MARSH ALLIA. 63 



Achenium flat. Pappus 2-awned ACTINOMERIS. 49 



Flowers yellow. Pappus 2 - 4-awned. 



Awns of the pappus deciduous HELIANTHUS. 47 



Awns of the pappus persistent, hispid upward. .... COREOPSIS 50 



Awns of the pappus persistent, hispid downward BIDENS. 52 



» » Heads with flowers variously imperfect 

 Marginal flowers pistillate. Central flowers perfect. 

 Pappus bristly. 



Scales of the involucre in a single row. BRECHTHITES. 72 



Scales of the involucre in 2 or more rows. 



Involucre persistent. Leaves sinuate-lobed. CONYZA. 26 



Involucre persistent. Leaves entire. Anthers tailed. . . PLUCHEA. 28 



Involucre persisteut. Leaves entire Anthers tailless. . . GNAPHALIUM. 70 



Involucre deciduous. Heads spiked PTEROCAULON. 29 



Pappus not bristly, 5-lobed TANACETUM. 67 



Pappus none ARTEMISIA. 68 



Marginal flowers pistillate. Central flowers staminate. 



Pappus none Style rigid, persistent. SOLIVA. 69 



Pappus none. Style deciduous. Heads nodding 1\X. 35 



Marginal flowers neutral. Central flowers perfect. .... CENTAUREA. 77 



* * « Heads dioecious or monoecious. 



Staminate and pistillate heads on the same plant. 



Fruiting involucre 1-seeded, naked or tubercled AMBROSIA. 36 



Fruiting involucre 2-seeded, armed with hooked spines. . . XANTHIUM. 37 



Staminate and pistillate heads on separate plants. 



Anthers tailed. Hoary herbs ANTENNARIA. 71 



Anthers tailless. Smooth shrubs BACCHARIS. 27 



§ 2. Heads radiate. 

 Rays pistillate 

 Flowers all fertile. 

 Receptacle naked. 

 Rays yellow. Leaves opposite. 



Pappus none FLAVERIA. 55 



Pappus scaly PECTIS. 4 



Rays yellow. Leaves alternate. 



Scales of the Involucre in 1 row SENEOIO. 74 



Scales of the involucre In 2 rows. ...... HELENIUM. 69 



Scales of the involucre in several rows INULA. 25 



