COMPOSITE. (COMPOSITE FAMILY.) 233 



38. Berlandiera. Achenes wingless, 5 - 12 in one row, without pappus. luner involucral 



scales obovate, outer smaller and more foliaeeous. Western. 



39. Chrysogonurn. Achenes wingless, about 5; pappus a one-sided 2 - 3-toothed crown. 



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



40. Engelmannia. Achenes wingless, 8 - 10 ; pappus a scarious hispid crown. Outer 



scales (about 10) leaf-like, inner coriaceous with green tips. Western. 



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



scales short, roundish, in 2 rows. 



* 2. Fertile flowers 1-5, the corolla noue or reduced to a tube ; staminate corolla funnel-form. 



Pappus none. 



+- Heads with 1-5 pistillate flowers. Receptacle chaffy. 



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



*- *- Heads of two sorts on the same plant, the upper 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. Xantliium. Scales of staminate involucre distinct. Fruit 1-4-celled, 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. 



i- Involucre double ; the outer forming a cup. 



45. Tetragonotheca. Outer involucre 4-leaved. Achenes obovoid ; pappus none. 



*- +- 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. 



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

 = Receptacle high, conical or columnar in fruit. Pappus none or a short crown. 



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



48. Echinacea. Rays rose-colored, pistillate, sterile. Acheues short, 4-sided. Chaff 



spiuescent. 



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



50. Lepachys. 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. Helianthus. 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. Verbesina. Involucral scales closely imbricated in 2 or more rows. 



54. Actinomeris. Scales few, soon deflexed. Achenes obovate, squarrosely 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 opposite. 



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. Achenes turbinate, 5- 



angled ; pappus of several chaffy scales, 

 -i- Leaves alternate, entire. Disk-flowers purplish. 



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



deeply honey-combed. 



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



