ORDEB 70. COMPOSITE. 409 



e Shrubs. Flower dioecious, the ? and $ in different heads BACCHARB. 85 



e Herbs. Stem winged. Heads spicato PTEROCAULON. 86 



Stem wingless. Heads corymbons, purplish i .PLUCHKA. 34 



Heads paniculate. Pappus reddish CONYZA. 82 



Pappus white ERECHTITES. 83 



f Receptacle chaffy except in the center FILAGO. 80 



f Ileceptacle naked. Heads dioecious ANTENNARIA. 79 



Heads heterogamous. Involucre erect GNAPIIALIUM. 73 



Involucre radiate HELICHRYSUM. 82 



g Scales dry, fadeless. Pappus of scale-like awns XERANTHEMUM. 81 



g Scales herbaceous. Flowers dioecious. Fruit a burr. XANTHIUM. 48 



Fls. all perfect. Pappus of 5 or 6 scales MARSHALLIA. G3 



Papp. of many bristles CABPIIEPIIOBUS. 6 



li Flowers yellow. Pappus 2 inversely hispid awns BIDENS. 53 



h Flowers yellow. Pappus 2 erectly hispid awns COREOPSIS. 57 



h Flowers whitish, dioecious. Anthers yellowish '. AMBROSIA. 45 



monoecious. Anthers yellow IVA. 44 



all perfect. Anthers black MELANTHERA. 47 



i Outer scales of the invol. leafy. Pappus none CARTHAMUS. 93 



i Outer scales pectinate or ciliate-fringed CENTAUREA. 91 



i Outer and inner scales obtuse, entire AMBERBOA. 92 



j Pappus plumous. Achenia obovate CYNARA. 83 



J Pappus plumous. Achenia oblong CIRSIUM. 95 



j Pappus scabrous, triple, each "row by 10s CNICUS. 94 



simple. Scales spinescent ONOPORDON. 95 



Scales hooked LAPP A. 97 



k Leaves opposite. Papp. scales deeply cleft into bristles DYSODIA. Cl 



k Leaves alternate. Rays fertile HELENIUM. 65 



Kays sterile. Receptacle naked or fimbriate GAILLARDIA. 62 



Receptacle areolate, LEPTOPODA. 66 



Receptacle deeply-celled BALDWIXIA. 67 



1 Leaves opposite. Involucre double, outer 8 united DAHLIA. 23 



1 Leaves opposite. Involucre single ; scales united TAGETES. 89 



1 Leaves alternate. Pappus of a few short awns or bristles BOLTONIA. 24 



Pappus a membranous margin MATRICARIA. 73 



Pappus 0. Rays fertile, disk sterile CALENDULA. 90 



Fls. all fert. Invol. scales equal BELLIS. 22 



Invol. broad, flat LEUCANTIIEMUM. 72 



Invol. hemispherical CHRYSANTHEMUM. 74 



m Rays neutral sterile, 312 ; Pappus simple GALATELLA. 16 



m Rays pistillate, fertile, about 5. Achenia very silky SKRICOCARPUS. 17 



812. Pappus double DIPLOPAPPUS. 19 



5 75. Pappus simple ASTER. 18 



4C 200, white. Scales equal ERIGERON. 20 



n Flowers dioecious, purplish. Leaves all radical NARDOSMIA. 14_, 



n Fls. all fertile. Outer pappus or very short bristles ERIGERON. 20 



Outer pappus a crown of short, pointed scales CALLISTEPHUS. 21 



o Flowers of the disk mostly sterile. Rays 30 JO PRIONOPSIS. 29 



O Fls. all fertile. Pappus double in the disk, none in the ray HETEROTHECA. 30 



Pappus double in both disk and ray CHRYSOPSIS. 81 



p Heads large, about 20-rayed. Pappus in one row INULA. 83 



p Heads very small, 1 15-rayed. Pappus 1 row, shorter than achenia.. .BRACIIYCH.ETA. 25 

 Pappus 1 row, tawny, longer than achenia.. ISOPAPPUS. 28 



Pappus irregularly 2-rowed, white SOLIDAGO. 26 



r Head solitary, on a scape with alternate bracts TUSSILAGO. 13 



r Heads corymbed, &c. Leaves .ilternate SENECIO. 86 



Leaves opposite ARNICA. 87 



s Shrubby. Pappus 4- toothed, obscure BORRICHIA. 37 



8 Herbaceous. Scales (the 4 outer) united into a cup TETRAGONOTHECA. 50 



Scales distinct. Achenia 4-angled. Pappus HELIOPSIS. 49 



Achenia flattened. Pappus ACMELJLA. 59 



Ach. flat, with a 2-awned pappus VEBBESINA. 60 



