178 COMPOSITE. (composite family.) 



Heads few-flow ered, 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. 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. 



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

 ■i- ■«- ■<- +- 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. . . 66, 66. 

 Marginal flowers pistillate and fertile. 

 Receptacle elongated ;md 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, 67 



* * # 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. 



§ 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 60. 



Heads 8 - 10-flowered. lieceptacle naked 13. 



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



Heads many-flowered. Receptacle 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. 



+- 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 riattish. . . 64. 



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



