178 COMPOSITE. (C03IPOSITE FAMILY.) 



Heads few-flowered, themselves aggregated into a compound or dense c.uster. . No. 2. 

 I!. : \v-il<>\vert'd or many -flowered. 



l;. (([, tju-le (wli.-n the flowers are pulled off) bristly hairy ..... 67,68,70. 



KtTi-ptHcle deeply honeycomb-like. . ........ 69. 



Pappus of plumose or bearded stiff bristles. Flowers purple ..... 4. 



Pappus of very plumose bristles. Flowers whitish. ...... 5. 



Pappus of slender but rather stiff rough bristles. . . . . 6, 7, 8, 20. 



Pappus of very soft and weak naked bristles. ...... 62, 63. 



- - Pappus composed of scales or chaff. 

 Receptacle naked. Leaves in whorls. . ....... 3. 



Receptacle naked. Leaves alternate. . . ...... 45. 



Receptacle bearing chaff among the flowers .......... 49. 



*- +- +- Pappus of 2 or few barbed awns or teeth. . . . 41, 42. 



*-*-!-- Pappus none, or a mere crown-like margin to the fruit. . .56. 



* * Flowers of two kinds in the same head. 



Marginal flowers neutral and sterile, either conspicuous or inconspicuous. . . 65, 66. 

 Marginal flowers pistillate and fertile. 

 Receptacle elongated and bearing broad chaff among the flowers. . . .60. 



Receptacle naked or bearing no conspicuous chaff. 

 Pappus of capillary bristles. Involucre imbricated ....... 23, 58, 59. 



Pappus of capillary bristles. Involucre merely one row of scales. . 14, 61. 



Pappus obsolete or none. 

 Achenia becoming much longer than the involucre ....... 11. 



Achenia not exceeding the involucre ........ 29, 56, 57. 



* * * Flowers of two kinds in separate heads ; one pistillate, the other staminate. 

 Heads dioecious ; both kinds many-flowered. Pappus capillary ..... 24, 59. 

 Heads monoecious ; the fertile 1 - 2-flowered and closed. Pappus none. . . .30, 31. 



J 2. Rays present ; i. e. the marginal flowers or some of them with ligulate corollas. 



* Pappus of capillary bristles. (Rays all pistillate.) 

 Rays occupying several rows, ... ...... 9, 10, 14 



Rays in one marginal row, and 



White, purple or blue, never yellow. ...... 12-16. 



Yellow, of the same color as the disk. 

 Pappus double, the outer short and minute ........ 21. 



Pappus simple. 



Scales of the involucre equal and all in one row. Leaves alternate. . . 63. 

 Scales of the involucre in 2 rows. Leaves opposite ...... 64. 



Scales of the involucre imbricated. Leaves alternate ...... 19, 22. 



* * Pappus a circle of chaffy scales, dissected into bristles. ... 44. 



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

 Heads several-flowered. Receptacle chaffy .......... 50. 



Heads 8 - 10-flowered. Receptacle naked .......... 1>. 



Heads many-flowered. Receptacle deeply honeycombed. ..'... 48. 



Heads many-flowered. Jloct-ptafle naked. ........ 46,47. 



* Pappus none, or a cup or crown, or of 2 or 3 awns, teeth, or chaffy scales corresponding 

 with the edges or angles of the achenium, often with intervening minute bristles or scales. 



i- Receptacle naked. 

 Arhenia flat, wing margined. Pappus of separate little bristles or awns. ... 16. 



Achenia flat, uiarginless. Pappus none. Km-i.t;u-le c-onical ...... 17. 



Achenia terete or angled. Pappus none. Receptacle ilattish. . 54. 



Achenia auglcd. Pappus a little cup or crown. Receptacle conical. . 66. 



