COMPOSIT.E. (composite FAMILY.) 233 



38. JBerlandiera. Achetfes wingless, 5 - 12 in one row, without papi>iis. Inner involucral 



scales obovate, outer smaller and more foliaceous. Western. 



39. Chrysogonum. Achenes wingless, about 5 ; pappus a one-sided 2 - ii-toothed crown 



Inner scales 5, chafl-like, the 5 outer longer and leaf-like. 



40. Sngelinannia. Achenes wingless, 8-10; pappus a searious hispid crown. Outer 



scales (about 101 leaf-like, inner coriaceous with green tips. Western. 



41. Partheniuni. Rays 5, very short, persistent. Pappus of 2 small scales. Involucral 



scales short, roundish, iu 2 rows. 



* 2. Fertile flowers 1-5, the corolla none or reduced to a tube ; staminate corolla funnel-form. 



Pappus none. 



-K Heads with l-b pistillate flowers. Receptacle chaffy. 



42. Iva. Achenes short, thick. Involucre of few roundish scales. 



*- •»- Heads of two sorts on the same plant, the upx^er staminate with an open cup-shaped 

 involucre, the lower pistillate, of 1-4 flowers in a closed bur-like involucre. 



43. Ambrosia. Scales of staminate involucre united. Fruit 1-seeded. 



44. Xanthium. Scales of staminate involucre distinct. Fruit 1-4-celIed, 1 -4-beaked. 



* 3. Heads radiate, or rarely discoid ; disk-flowers all perfect and fertile. Anthers blackish. 



Pappus none, or a crown or cup, or of one or two chaffy awns, never capillary, nor of 

 several uniform chaffy scales. — Leaves more commonly opposite. 



•*- Involucre double ; the outer forming a cup. 



46. Tetragonotlieca. Outer involucre 4-leaved. Achenes obovoid ; papi)us none- 



t- -t~ Involucre of one or more rows of separate scales. 



++ Chaff of the flat receptacle bristle-shaped. 



46. !Eclipta. Ray short. Involucral scales 10-12, in two rows, herbaceous. 



++ ++ Chaff scale-like, embracing or subtending the achenes. 

 = Rece})tacle high, conical or colnmnar in fruit. Pappus none or a short crown. 



47. Heliopsis. Rays fertile. Achenes 4-sided. Leaves opposite. 



48. Echinacea. Rays rose-colored, pistillate, sterile. Achenes short, 4-sided. Chafi 



spiiieseent. 



49. Kudbeckia. Rays neutral. Achenes 4-sided, flat at the top, marginless. 



50. Iicpachys. Rays few, neutral. Achenes flattened laterally and margined. 



= = Receptacle flat to convex. Achenes not winged nor very flat. 



51. Borrichia. Achenes 3- 4-angled; pappus a short 4-toothed crown. Shrubby. 



52. Heliaiitlius. Achenes flattened, bearing 2 very deciduous chaffy pointed scales. 



= = = Receptacle convex (rarely conical). Achenes flat-compressed laterally, winged or 

 wingless, 2-awned. Leaves decurrent. 



53. Terbesina. Involucral scales closely imbricated in 2 or more rows. 



54. Actinomeris. Scales few, soon deflexed. Achenes obovate, scjuarrosely spreading. 



* 4. Rays few, neutral, or wanting. Achenes obcompressed, i. e., flattened parallel with the 



scales of the involucre (rarely terete). Involucre double ; the outer spreading and often 

 foliaceous. Receptacle flat. Leaves opi»osite. 



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



barbed upward, sometimes obsolete or a mere crown. 



56. Bidens. Pappus of 2 or more rigid and persistent downwardly barbed awns or teeth. 



57. Thelesperma. Inner involucre connate to the middle. Achenes terete. Awns re- 



trorsely bearded. 



* 5. Heads radiate or discoid ; disk-flowers all perfect .and fertile. A.chenes turbinate, 5- 



angled ; pappus of several chaffy scales, 

 •t- Leaves alternate, entire. Disk-flowers purplish, 



58. Baldwinia. Rays numerous, long, neutral. Involucre much imbricated. Receptaelf 



(lee]ily honey-conibed. 



59. Marshallia Rays none. Involucre of narrow leafy equal scales. .Receptacle chaffy 



