220 COMPOSITE. (composite family.) 



* # * Rays sterile, neutral : achenia obcom pressed, i. e. flattened parallel with the scales of the 

 involucre, the faces looking inwards and outwards. Involucre double ; the outer spreading 

 and often foliaceous. Receptacle flat. 



41. Coreopsis. Pappus of 2 (or rarely more) scales, teeth, or awns, which are naked or 



barbed upwards, sometimes obsolete or a mere crown. 



42. Bidens. Pappus of 2 or more rigid and persistent downwardly barbed awDS or teeth. 



* # * * Rays pistillate or fertile (rarely none) : achenia laterally flattened, 2-awned. 



43. Verbesina. Rays few and small, or rarely none. Receptacle convex. Achenia some- 



times winged. 

 Subtribe 3. Tagitineic, Heads commonly radiate ; the rays ligulate ; the disk-flowers 

 all perfect and fertile. Receptacle naked, fiat. Scales of the involucre united into a cup. 

 Pappus various. — Herbage strong-scented (as in Tagetes of the gardens), being dotted with 

 large pellucid glands containing a volatile oil. 



44. Dysodia. Pappus a row of chaffy scales dissected into many bristles. 



Subtribe 4. Helenieae. Heads radiate or sometimes discoid ; the disk-flowers perfect. 

 Pappus a circle of several chaffy scales. Anthers tailless. 



* Receptacle naked (not chaffy nor honeycombed.) 



45. Hymenopappus. Rays none. Receptacle flat. Scales of the involucre colored. 

 4.V. Actiiit'lla. Rays pistillate, merely toothed. Receptacle elevated. Tnvolucre appressed. 



46. Helenium. Rays pistillate, 3 - 5-cleft. Receptacle elevated. Involucre small, reflexed. 



47. lieptopoda. Rays neutral or sterile : otherwise as No 46. 



* * Receptacle deeply pitted, like honeycomb. 



48. Baldwinia. Rays numerous: neutral, elongated. Involucre much imbricated. 



# * # Receptacle chaffy. 



49. Mars hall ia. Rays none. Involucre of many narrow and foliaceous scales. 



50. Galinsoga. Rays 4 or 5, short, pistillate, whitish ; the disk yellow. Involucre of 4 or 



5 ovate and thin scales. 



Subtribe 5. Anthemideae. Heads radiate or discoid ; the perfect flowers sometimes 

 infertile, and the pistillate flowers rarely tubular. Pappus a short crown or none. Other- 

 wise nearly as Subtribe 4. 



* Receptacle chaffy, at least in part : rays ligulate. 



51. Maruta. Rays neutral. Achenia obovoid and many-ribbed. Pappus none. 



52. A nt 1) t mis. Rays pistillate. Achenia terete or 4-anguIar. Pappus minute or none. 



53. Achillea. Rays pistillate, short. Achenia flattened and margined. 



* * Receptacle naked. 



54. Lencanthemnm. Rays numerous, pistillate. Receptacle flattish. Achenia striate 



or ribbed. Pappus none. 



55. Matricaria. Rays pistillate, or none, and then all the flowers perfect. Receptacle con- 



ical. Pappus crown-like or none. 



56. Tanacetum. Rays none, but the marginal flowers pistillate. Achenia broad at the 



top. Pappus a short crown. 



57. Artemisia. Rays none ; some of the outer flowers often pistillate. Achenia narrow at 



the top. Pappus none. 



Subtribe 6. Gnaphalinere. Heads all discoid, with tubular corollas; those of the 

 fertile flowers filiform. Anthers with tails at their base. Pappus of capillary bristles. 

 Flocculent-woolly herbs : leaves alternate. 



58. Gnaphalliim. Receptacle naked, flat. , Heads containing both perfect and pistillate 



flowers. Bristles of the pappus all slender. 



59. Antennaria. Receptacle naked, flat. Heads dioecious, or nearly so. Pappus of the 



staminate flowers thickened or club-shaped at the summit. 



60. Filago. Receptacle columnar or top-shaped, chaffy. Pappus of the inner flowers capil- 



lary, of the outer often none. 



