244 LIT. COMPOSITE 
Ray-flowers lilac or purple. Disk-flowers yellow. 
Ray-flowers in 1 or 2 series 10. Aster. 
Ray-flowers in more than 2 series . . .11. Erigeron. 
Ray-flowers white. Disk-flowers white. Heads solitary 48. Gerbei-a. 
* * Pappus of bristles or scales 
(sometimes none in Rhynchospermum and Spilanthes) 
Receptacle naked. Pappus of 3-8 bristles, sometimes 
none. Achenes beaked 9. Rhynchospermum. 
Receptacle covered with broad, folded scales each 
enclosing several flowers. Pappus of 2-5 minute 
teeth 27. Eclipta. 
Receptacle covered with concave scales each partially 
enclosing a single flower. 
Heads flat, in. diam 29. Blainvillea. 
Heads Conical, ^-| in. long. Pappus sometimes 
wanting 30. Spilanthes. 
Receptacle covered with narrow, flat scales nearly as 
long as the flowers. Pappus of 2-3 stiff-barbed 
bristles 31. Bidens .’ 
Receptacle covered with small, 3-toothed scales. 
Pappus of several fringed scales . . . .32. Galinsoga. 
* * * Pappus none (see also Rhynchospermum and Spilanthes) 
Leaves ovate, lanceolate or triangular. 
Involucral bracts glandular ..... 26. Siegesbeckia. 
Involucral bracts not glandular. 
Heads hemispheric. Ligules minute. Receptacle 
naked ....... 8. Myriactis. 
Heads flat. Ligules broad. Receptacle scaly . 28. Sclerocarpus. 
Leaves pinnatisect ; segments linear . . . .33. Achillea. 
III. Ligulate heads 
* Pappus of simple hairs 
Achenes beaked. 
Beak of achenes dilated at the tip 55. Lactuca. 
Beak of achenes not dilated at the tip. 
Heads corymbose. Stems leafy . . .51. Crepis. 2 
Heads solitary. Leaves all radical . . .54. Taraxacum. 
Achenes not beaked. 
Receptacle hairy or bristly. 
Stems naked. Receptacle covered with long 
hairs ........ 52. Pterotheca. 
Stems leafy. Receptacle covered with short 
bristles ........ 53. Hieracium. 
Receptacle naked. 
Flowers purple or white 56. Prenanthes. 
Flowers yellow. 
Juice white, milky. 
Stem-leaves none or few, small and stalked 51. Crepis. 3 
Stem-leaves numerous, large, stem-clasping 57. Sonchus. 
Juice yellow. Margins of leaves beset with 
minute, white teeth 58. Launce.a. 
’ Except B. tripartita, which has discoid heads. 2 Except C. japonica, 
which has achenes without beaks. 3 C. japonica only ; the others have 
beaked achenes. 
