178 COMPOSITE. (COMPOSITE FAMILY.) 



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

 Heads separate, few-flowered or many-flowered. 



Receptacle (when the flowers are pulled off ) bristly hairy 67, 68, 70. 



Receptacle deeply honeycomb-like. . ........ 69. 



Receptacle naked. 

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



Pappus of very plumose bristles. Flowers whitish .. * , & 



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



Pappus of very soft and weak naked bristles. 62, 68. 



- i- Pappus composed of scales or chaff. 



Receptacle naked. Leaves in whorls. . ;;> : i ''"'* ' . . . 8. 



Receptacle naked. Leaves alternate. . . . . . i . . . . 46. 



Receptacle bearing chaff among the flowers. . . . . _ . . . ..-, .^i -^ s 49. 



*-*- i- Pappus of 2 or few barbed awns or teeth. . -.;, **> 42 * 

 --- Pappus none, or a mere crown-like margin to the fruit. . .65. 



* * Flowers of two kinds in the same head. 



Marginal flowers neutral and sterile, either conspicuous or inconspicuous. ; . , ^f. 66, 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. . .<.:,*;' '* .23,68,69. 

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



Pappus obsolete or none. 



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

 Achenia not exceeding the involucre. . - f _ . i, , , : j. -i > i ! .;:*' . 29, 66, 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. . .-.. 80,81. 



$ 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, . . . r ;.>.,... 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 hi one row. Leaves alternate. . . 63. 



Scales of the involucre hi 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 "'. 60. 



Heads 8 - 10-flowered. Receptacle naked -:i - . . '-'. . IS. 



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



Heads many-flowered. Keceptacle 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. 



t- Receptacle naked. 

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



Achenia flat, marginless. Pappus none. Receptacle conical 17. 



Achenia terete or angled. Pappus none. Receptacle flattish. 64. 



Achenia angled. Pappus a little cup or crown. Receptacle conical. . 65. 



