COMPOSIT.E. (COMPOSITi: FAMILY.) 233 



38. Berlandiera. Achenes wiiiyless, 5-12 in one ruw, without i»appus. Inner involucral 



sc-ak'n oliovate, outor smaller and more foliaceous. Western. 



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



Inmr .scales :,, chatf-like, tlic 5 outer longer and leaf-like. 



40. £ng:eliiiaiinia. Achenes wingless, 8-10; i>appus a scarious liispid crown. Outer 



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



41. Partheniuin. Rjiys 5, very short, persistent. Pappus of 2 small scales. Involucral 



scales short, roundish, in 2 rows. 



• 2. Fertile flowers 1-5, the corolla none or reduced to a tube ; starninate corolla fuunel-fonn. 



Pappus none. 



■1- Heads with 1-5 pistillate flowers. Receptacle chafi'y. 



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



•♦- -t- Heads of two sorts on the same plant, the upper starninate 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. Xanthiuin. Scales of staminate involucre distinct. Fruit 1-4-celled, 1-4-beaked. 



• 3. Heads radiate, or rarely discoid ; disk-flowei-s 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 chafi'y scales. — Leiives more commonly opposite, 

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



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



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

 ++ Chaff of the flat receptacle bristle-shaped. 



46. £clipta. Ray short. Involucral scales 10-12, in two rows, herbaceous. 



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

 = Recei)tacle 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. Achenes short, 4-sided. Chaff 



spinescent. 



49. liudbeckla. Rays neutral. Achenes 4-sided, flat at the toji, 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. Hellanthus. 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. Actinonieris. Scales few, soon deflexed. Achenes obovate, squarrosely spreading. 



• 4. Rays few, neutral, or wantnig. Achenes obcompressed, i. e., flattened parallel with the 



scales of the involucre (rarely terete). Involucre dcmble ; 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 uj)ward, sometimes obsolete or a mere crown. 



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



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



tro rsely bearded. 



• 5. Heads radiate or discoid ; disk-flowers all perfect and fertile. Achenes turbinate, 5- 



angled ; pappus of sevenil chaffy scales. 

 ■»- 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 chafTi'. 



