FLOWERING PLANTS AND FERNS OF ARIZONA 873 



12. Phyllaries not with conspicuous whitish or yellowish tips and 



margins; achenes otherwise (13). 



13. Heads solitary or cymose 108. Matricaria. 



13. Heads in spikes or racemes, these often panicled. 

 9 110. Artemisia. 



5. Flowers not all hermaphrodite, the outer ones pistillate and fertile, the inner 

 ones hermaphrodite but often sterile (14). 

 14. Plants woolly, annual, dwarf (15). 



15. Bracts subtending the pistillate flowers completely enclosing them, and 



tipped with a hyaline appendage 32. Sttlocline. 



15. Bracts subtending the pistillate flowers more or less open, not com- 

 pletely enclosing the flowers (16). 



16. Pales of the receptacle nattish 33. Evax. 



16. Pales of the receptacle, at least the outer ones, boat-shaped. 



34. Filago. 

 14. Plants not woolly or, if so, then perennial (17). 



17. Receptacle not chaffy 110. Artemisia. 



17. Receptacle chaffy, at least toward the margin (18). 



18. Achenes densely long-villous; leaves or their lobes linear-filiform. 



46. Oxytenia. 

 18. Achenes not long-villous; leaves or their lobes not linear-filiform (19). 



19. Achenes with pectinate or toothed wings 47. Dicoria. 



19. Achenes not with pectinate or toothed wings (20). 

 20. Pistillate flowers 6 to 8; achenes with an acute margin and a 

 terminal apiculation, falling away at maturity with the pales 



of the opposed disk flowers 44. Parthenice. 



20. Pistillate flowers 5 ; achenes otherwise 45. I va. 



D. Hermaphrodite flowers with a tubular, regular or nearly regular corolla; 

 rays none or vestigial; pappus present, of awns or scales or both, these 

 sometimes united into a low chaffy crown. 



1. Receptacle chaffy (2). 



2. Pappus of about 15 plumose awns 77. Bebbia. 



2. Pappus not of plumose awns (3). 



3. Pappus of numerous flattened bristles 30. Baccharis. 



3. Pappus of 1 to 4 teeth, squamellae, awns, or paleae (4). 



4. Achenes with pectinate or toothed wings 47. Dicoria. 



4. Achenes not with pectinate or toothed wings (5). 



5. Awns or teeth not retrorsely barbed; plants shrubby (6). 



6. Achenes somewhat thickened, not notably ciliate on the margin. 



63. Flourensia. 



6. Achenes very flat, conspicuously ciliate on the margin. 



64. Encelia. 

 5. Awns or teeth retrorsely barbed; plants herbaceous (7). 



7. Inner phyllaries united about to the middle, forming a cup. 



74. Thelesperma. 



7. Inner phyllaries not united 75. Bidexs. 



1. Receptacle not chaffy, sometimes setose or fimbrillate (8). 

 8. Heads 1 -flowered, crowded in dense glomerules; involucres of the individual 



heads tubular, 5- or 6-toothed at tip 38. Lagascea. 



8. Heads several- or many-flowered (9). 



9. Plants strictly dioecious, the heads on some plants entirely pistillate, on 

 others with hermaphrodite but sterile and functionally staminate 



flowers 30. Baccharis. 



9. Plants not dioecious (10). 



10. Receptacle densely setose all over; thistlelike herbs (11). 



11. Pappus of numerous slender plumose paleae, united at base and 

 deciduous in a ring 118. Cynara. 



11. Pappus of numerous setae or paleae, not united at base, separately 



deciduous 120. Cextaurea. 



10. Receptacle naked, fimbrillate, or sparsely setose; plants not thistle- 

 like (12). 



12. Pappus of 2 to 8 caducous awns; plants usually strongly glutinous. 



10. Grindelia. 

 12. Pappus otherwise (13). 



13. Pappus of numerous graduated bristles, the inner ones somewhat 



flattened and paleaceous; low shrub, with crowded, subterete, 

 impressed-puiKtate leaves 112. Peucephyllum. 



