OEDEB 70. COMPOSITES. 409 



e Shrubs. Flower dioecious, the $ and 3 in different heads BACCHABIS. 35 



e Herbs. Stem winged. Heads spicate PTEBOCAULOX. 86 



Stem wingless. Heads corymbous, pnrplish PLCCHBA. 34 



Heads paniculate. Pappus reddish COSYZA. 82 



Pappus white EIJECHTITES. 88 



f Receptacle chaffy except in the center FILAGO. 80 



f Receptacle naked. Heads dioecious. ASTERS ARIA. 79 



Heads heterogamous. Involucre erect GSAPH ALICM. 78 



Involucre radiate HELICHRYSUM. 82 



g Scales dry, fadeless. Pappus of scale-like awns XE R A> THEMCM. 81 



g Scales herbaceous. Floweijs dioecious. Fruit a burr XANTHIXTM. 46 



Fls. all perfect. Pappus of 5 or 6 scales MABSUALLIA. 68 



Papp. of many bristles CARPHEPIIORUS. 6 



h Flowers yellow. Pappus 2 inversely hispid awns BIDENS. 58 



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 



Pappus plumous. Achenia obovate C YNARA. 88 



j Pappus plnmons. Achenia oblong CIESLCM. 96 



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



simple. Scales spinescent ONOPOEDON. 95 



Scales hooked. LAPPA. 97 



k Leaves opposite. Papp. scales deeply cleft into bristles . .DTSODIA. 61 



k Leaves alternate. Rays fertile HELESIUM. 65 



Rays sterile. Receptacle naked or fimbriate GAILLARDIA. 62 



Receptacle areolate, LEPTOPODA. 68 



Receptacle deeply-celled BALDWINIA. 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 M ATRIC ARIA. 73 



Pappus ft. Rays fertile, disk sterile CALENDULA. 90 



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



Invol. broad, flat LECCANTHEMITM. 72 



Invol. hemispherical CHRYSANTHEMUM. 74 



m Rays nutral, sterile, 812 ; Pappus simple GALATELLA. 16 



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



S 12. Pappus double DIPLOPAPPUB. 19 



5 "5. Pappus simple ASTER. 18 



tC 200, white. Scales equal EKIGEBON. 20 



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



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



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



o Flowers of the disk mostly sterile. Rays 30 40 PEIOXOPSIS. 29 



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



Pappus double in both disk and ray CHRYSOPSIS. 31 



p Heads large, about 20-rayed. Pappus in one row INCLA. 88 



p Heads very small, 115- rayed. Pappus 1 row, shorter than achenia. . .BRACHYCH/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 TCSSILAGO. 18 



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



Leaves opposite ARNICA. 87 



8 Shrubby. Pappus 4-toothed, obscure BORRICHIA. 87 



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



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



Achenia flattened. Pappus ACMELLA. 59 



Ach. flat, with a 2-awned pappus VERBESINA. 6Q 



