778 



COMPOSITAE (COMPOSITE FAMILY) 



Fertile involucre armed with 2 or more rows of spines or these 



irregularly distributed 41. ^rans^^. 



Braete of staminate involucre distinct ; fertile involucre horned in 



fruit and very prickly ... ... 42. Xant7iiv/m. 



§ 2. Mays present^ i.e. the marginal Jlowers or some of them with straplik^ 



corollas. 



^ Pappus of capillary bristles, at least in the disk-flowers; ray flowers pistillate I. 



I. Eays occupying several rows. 



Kays yellow T4. Tussilago. 



Eays white or purplish. 



Leaves cordate 75. Petasitea. 



Leaves not cordate 28, Erig&r(m. 



I. Rays in one marginal row m, 

 m, Kays not yellow. 



Upper part of stem bearing ovate or lanceolate phyllodia . , .75. Peiasites. 

 Phyllodia none. 



Rays and disk-flowers similarly colored 15. SoUdago. 



Rays and disk -flowers of contrasting colors. 



Rays 4 or 5 ... . 24. SericocarpuB, 



Rays numerous. 

 Involucral bracts subequal, narrow, chiefly in 1 series . . 23. EHg&r<m. 

 Involucral bracts imbricated in several mostly unequal series 22. Aat&r, 

 m. Eays yellow n. 



n. Pappus (at least in the disk-flowers) double, the outer short and 

 minute. 

 Ray-flowers with pappus of capillary bristles ... .14. CJi/ryHomis. 



Eay-flowers with coroniform pappus . . ... 13. Hetm'omeca. 



II.. Pappus simple. 



Leaves opposite .... 76. Arivica. 



Leaves alternate. 

 Involucral bracts equal and in 1 row (though often calyculate) . 79. Senedo. 

 Involucral bracts imbricated in several series. 

 Heads 8-5 cm. in diameter ... .81. Inula. 



Heads 2 cm. or less In diameter. 

 Pappus of several very narrow scales rather than truly 

 capillary bristles. 

 Pappus of disk-flowers nearly or quite as long as the 



corolla 12. ^ mpMachyris. 



Pappus of disk-flowers much shorter than the corolla -. 11. Outierresia. 

 Pappus-bristles hair-like. 

 Pappus-bristles equal ... . .15. Solidago. 



Pappus-bi-istles unequal .... 17. Aplopappus. 



* * Pappus a circle of awns or rigid bristles at least in the disk- 

 flowers . . . 10. Grindelia. 



* * * Pappus a circle of chaffy scales dissected into bristles . 66. Thjsaodia. 



* * * * Pappus a circle of thin chaffy scales or short chaffy bristles o. 



o. Eeceptacle deeply honeycombed ... .... 57. Baldtt/ina, 



0. Eeceptacle not deeply honeycombed, naked. 



Eeceptacle flattish ; heads small, few-flowered. 

 Leaves serrate, the lower heart-shaped .... ,16. BracJiychasta. 



Leaves entire, linear, never cordate 11. Guiierreeia. 



Eeceptacle elevated, strongly convex ; heads many-flowered. 



Scapose 63. Aciinea. 



Leafy-stemmed: leaves decurrent . . ... 64. Ilelenium. 



o. Receptacle not deeply honeycombed, chafFy. 



Heads less than 1 cm. in diameter . . . . 59. Gaiinaoga. 



Heads more than 1 cm. in diameter . 65. GaillardJn. 



♦ * * * * Pappus none, or a cvxp or crown, or of a or 3 awns, teeth or chaffy scales corresponding 



with the edges or angles of the achene, often with intervening minute bristles 

 or scales. 



-J- Eeceptaclb naked p. 

 p. Achenes flattened. 



Achenes wing-margined; pappus present ... 21. Boltimia. 



Achenes marginless ; pappus none .19. Bellu. 



p. Achenes tei-ete or prismatic. 



Receptacle conical 69. Matricaria. 



Eeceptacle flattish. 

 Heads very .small ; ray-flowers mostly 1 , . .60. Flaveria. 



Heads rather large; rays numerous 70. ChryHantheinum 



p. Achenes fusiform ; pappus of few scales, usually alternating with awns 20. Cbaeiopappa, 



+- -i- Receptacle chaffy q, 

 q- Eays neutral (rarely pistillate but sterile); the disk-flowers perfect 

 and fertile. 



