Obdeb 70.— COMPOSITE. 409 



e Shrubs. Flower dioocioQS, the ? and & In different heads .. Baociiaris. 35 



a Herbs.— Stem winded. Heads spicate Ptebocaulon. 36 



Stem -wingless.— Heads corymbous, purplish Pluchea. 34 



—Heads paniculate. — Pappus reddish Conyza. 32 



—Pappus white.. Erechtites. S3 



f Receptacle chaffy except in the center Filago. 80 



f Receptacle naked.— Heads dicecious Antennabia. 79 



— Heads heterogamous. — Involucro erect Gnaphalicm. 73 



— Involucre radiate IIeliciirysum. 82 



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



g Scales herbaceous.— Flowers dioecious. Fruit a burr Xantihum. 46 



— Fls. all perfect.— Pappus of 5 or 6 scales Marsiiallia. CS 



— rapp. of many bristles C arpiiepiiorus. 6 



h Flowers yellow. Pappus 2 inversely hispid awns Bidens. 53 



h Flowers yellow. Pappus 2 erectly hispid awns Coreopsis. 5T 



h Flowers whitish,— dicecious. Anthers yellowish Ambrosia. 43 



monoecious. Anthers yellow Iva. 44 



—all perfect. Anthers black Mel antiiera. 4T 



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



i Outer scales pectinate or ciliate-fringed Centaukka. 91 



i Outer and inner scales obtuse, entire Amberboa. 92 



J Pappus plumous. Achenia obovatc Cynara. 88 



J Pappus plumous. Achenia oblong Cirsium. 90 



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



—simple.— Scales spinescent Onopordon. 95 



—Scales hooked Lappa. 9T 



k Leaves opposite. Papp. scales deeply cleft into bristles Dysodia. CI 



k Leaves alternate.— Pvays fertile Helenium. 65 



—Rays sterile.— Receptacle naked or fimbriate Gaillardia. G2 



—Receptacle areolatc, Leptopoda. 60 



Receptacle deeply-celled Baldwinia. 6T 



1 Leaves opposite. Involucre double, outer S united Dahlia. 23 



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



I Leaves alternate.— Pappus of a few short awns or bristles Boltonia. 24 



— Pappus a membranous margin Matricaria. 78 



—Pappus 0.— Rays fertile, disk sterile Calendula. 90 



—Fls. all fort.— Invol. scales equal Bellis. 22 



—Invol. broad, flat Leucanthemum. 72 



— Invol. hemispherical Chrysanthemum. 74 



m Rays nutral, sterile, 0—12 ; Pappus simple Galatella. 15 



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



— S— 12. Pappus double Diplopappus. 19 



— 5 — 75. Pappus simple Aster. 18 



_4C— 200, white. Scales equal Eeigeron. 20 



II Flowers dioecious, purplish. Leaves all radical Nardosmia. 14 



n Fls. all fertile.— Outer pappus or very short bristles Ebigep.ox. 20 



— Outer pappus a crown of short, pointed scales Callistepiius. 21 



O Flowers of the disk mostly sterile. Rays 30—40 Peionopsis. 29 



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



—Pappus double in both disk and x/ny Ciikysopsis. 31 



p neads large, about 20-raycd. Pappus in one row Inula. 33 



p Heads very small, 1 — 15-rayed.— Pappus 1 row, shorter than achenia.. .BRACHYCii.Hf'A. 25 

 — Pappus 1 row, tawny, longer than achenia..IsoPAPPU6. 28 



— Pappus irregularly 2-rowed, white Solid ago. 26 



r nead solitary, on a scapo with alternate bracts Tussilago. 13 



r Heads corymbed, &c. — Leaves alternate Senecio. 86 



—Leaves opposite Arnica. S7 



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



U Herbaceous.— Scales (the 4 outer) united into a cup Trtragonothf-ca. 50 



—Scales distinct.— Achenia 4-angled. Pappus IIeliopsis. 49 



—Achenia flattened. Pappus Acmella. 59 



— Ach. flat, with a 2-awncd pappus Vkrbesina. 6» 



