186 



composita;. (coMi'OSirt; family.) 



Rays white or purpic. No. 



Pappus none. . LEUCANTIIKMLM 66 



Pappus bristly EIUOEUON. 17 



Receptacle pitted. 

 Kays white or purple. 



Pappus double. DTPLOPAPPU.«. 18 



Pappus single. Rays about 5. Aclieuia silky. . . SEIUCOOAItPU.S 15 



Pappus single. Rays numerous. Pappus bristly ASTER. 16 



Pappus single. Rays nuuicrous. Pappus scaly. . . BOLTONIA. 19 



Rays yellow. 



Pappus double, of the ray and disk flowers alike. . . . ClIUYSOPSIP. 24 



Papjius double, of the ray flowers none IlEl'EUOTIIECA. £3 



Pappus single. 



Leaves opposite. Heads large, single or corymbose. . . . AKNICA. 76 



Ix^aves alternate. Heads racemed or clustered. . . . SOLIDAGO. 20 



Leaves alternate Heads panicled ISOPAPPU?. 22 



Receptacle chaffy. 

 Involucre double, the outer 4-leaved, 4-angled. . . . TETRAGOXOTHECW. 43 

 Involucre imbricated or spreading. 



Maritime shrubs. Pappus 4-toothed. LOIIUICHIA. 31» 



Herbs. 

 Receptacle conical or elongated. 



Rays persistent. Corolla-lobes velvety ZINNIA. 41 



Rays deciduous. Achenia 3 - 4-angled IIRLIOPSIS. 42 



Rays deciduous. Achenia compressed SPILANTIIES. 53 



Receptacle flat. 



Leaves lolled, alternate ACHILLEA. 65 



Leaves not lobcd. Pappus 2-awned. .... VERBESIXA. 54 



Leaves not lobcd. Pappus none. ...... ECLIPTA. 38 



Flowers of the disk sterile. 



Rays yellow. Pappus none POLY.MNI.\. 30 



Rays yellow. Pappus a toothed crown . CIIRY'SOGOXUM. 31 



Rays yellow. Pappus 2-toothed or awned. Achenia winged. . . SILPIIIUM. 32 

 Rays yellow. Pappus 2-toothed or awned. Achenia wiDgles:^. . BERLAXDIEUA. 33 



Rays white. Receptiicle conical PARTIIEXIUM. 34 



Rays neutral (without pistils). 

 Receptacle naked, or nearly so. 

 Achenia villous. Pappus scaly, long-awned. .... G.\ILLARDIA. 56 



Achenia smooth or the angles hairy. Pappus awnless. . . . LEPTOPODA. 60 

 Receptacle deeply pitted. 



Margins of the pits entire. Perennial B.4LDWINIA. 61 



Margins of the pits toothed. Annual ACTINOSPERMUM. 62 



Receptacle chaffy throughout. 



Involucre double. Pappus 2 - 4-awned. 



Awns of the pappus hispid upward COREOPSIS. 50 



Awns of the pappus hispid downward. Achenia beakless. . . BIDEXS. 52 



Awns of the pappus hispid downward. Achenia beaked. . . • COSMOS. 51 

 Involucre simple or imbricate. 



Pappus a cup-shaped border, or none. 

 Chaff of the receptacle elongated, spine-pointed. . . . ECHIN^4.CEA. 44 

 Chaff of the receptacle not elongated nor spine-pointed. . . RUDBECKIA. 45 

 Pappus 2 - 4-awned. 

 Achenia winged. Leaves divided. Receptacle elongated. . . LEPACHTS. 46 

 Achenia winged. Leaves undivided. Receptacle convex. . ACTIXOMERIS. 49 

 Achenia wingless. Awns of the pappus deciduous. . . HELIAXTHUS. 47 

 Achenia wingless. Awns of the pappus persistent. . . HELIANTHELLA. 48 

 Receptacle chaffy at the apex. Achenia ribbed MARCTA. 64 



