COMPOSITE. (COMPOSITE FAMILY.) 217 



$ 2. Bays 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 12-15. 



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 two 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 18. 



Heads many-flowered. Receptacle deeply honeycombed 48. 



Heads many-flowered. Receptacle naked 45J, 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. 



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



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



Achenia angled. Pappus a little cup or crown. Receptacle conical. . . . .55. 



,-t- *- Receptacle chaffy. 



Bays neutral (rarely pistillate but sterile) ; the disk-flower s perfect and fertile. 

 Receptacle elevated (varying from strongly convex to columnar), and 



Chaffy only at the summit ; the chaff deciduous. Pappus none 51. 



Chaffy throughout. Achenia flattened laterally if at all 36-40. 



Receptacle flat or flattish. Achenia flattened parallel with the scales or chaff. . 41,42. 

 Bays pistillate and fertile ; the disk-flowers also perfect and fertile. 



Achenia much flattened laterally, 1 - 2-awned . 43. 



Achenia flattened parallel with the scales and chaff. Pappus none. . . .53. 

 Achenia 3 - 4-angular, terete or laterally flattish, awnless. 



Receptacle convex or conical. Leaves alternate, dissected. 52. 



Receptacle conical. Leaves opposite simple. 



Achenia obovoid. Involucre a leafy cup 32. 



Achenia 4-angular. Involucre of separate scales 35. 



Receptacle flat. Leaves opposite and simple . . 33, 34. 



Rays pistillate and fertile : the disk-flowers staminate and sterile (pistil imperfect). 



Receptacle chaffy 25-28. 



Systematic Synopsis. 



Tribe I. VERNONIACEJE. Heads discoid ; the flowers all alike, perfect and tubu- 

 lar. Branches of the style long and slender, terete, thread-shaped, minutely bristly-hairy 

 . all over. Leaves alternate or scattered. 



1. Vernonla. Heads several -many-flowered, separate. Involucre of many scales. Pap- 



pus of many capillary bristles. 



2. El e ph a to pus. Heads 3 - 5-flowered, several crowded together into a compound head. 



Involucre of 8 scales. Pappus of several chaffy bristles. 



Tribe II. EUP ATORIACE^. Heads discoid, the flowers all alike, perfect and tu- 

 bular ; or in a few cases dissimilar, and the outer ones ligulate. Branches of the style 

 thickened upwards or club-shaped, obtuse, very minutely and uniformly pubescent 5 the 

 fltigmatic lines indistinct. 



