WOOTON AND STANDLEY—FLORA OF NEW MEXICO. 639 
Plants not spiny; leaves not scalelike. 
Leaves very thick and rigid, spinose-toothed. 
37. HERRICKIA (p. 686). 
Leaves thin, not spinose-toothed. 
Bracts broad, with a distinct keel or midvein, not at all 
foliaceous; plants more or less glaucous. 
36. EucEPHALUS (p. 686). 
“ Bracts mostly narrow, when broad neither keeled nor with 
a prominent midvein; plants not glaucous, 
35. ASTER (p. 682), 
Rays yellow or wanting. 
Pappus none to coroniform, paleaceous, or of few rigid awns, never of numerous 
capillary bristles. 
Pappus of few deciduous stout awns; heads large, usually viscid. 
11. GRINDELIA (p. 653). 
Pappus not of awns, rarely a few in some of the disk flowers, paleaceous or 
wanting; heads various. 
Pappus altogether wanting; rays short, not surpassing the disk corollas; 
perennial plant, woody at the base.......12. GymNosPerMA (p. 656). 
Pappus present but often obscure; rays much surpassing the disk corollas; 
annuals or perennials, , 
Rays 12, 1 cm. long; pappus coroniform; plant annual; heads large, 
hemispheric wee eee eee eee eee eens 13. XANTHOCEPHALUM (p. 656). 
Rays 10 or less, less than 5 mm. long; pappus not coroniform; annuals or 
perennials; heads small. 
Only the ray flowers fertile; pappus in disk flowers of aristiform paleze 
dilated at the base. ................14. Ampuiacuynis (p. 656), 
All or most of the disk flowers as well as those of the rays fertile; pappus 
of numerous palez, those of the ray small. 
15. GUTIERREZIA (p. 656), 
Pappus, at least in part, of numerous capillary bristles. 
Ray achenes usually without pappus, never with numerous bristles, 
16. HeTEROTHECA (p. 658), 
All achenes with pappus of numerous capillary bristles. 
Pappus of 2 series, the inner of capillary bristles, the outer of scales or short 
bristles... 2.2.22... eee eee eee eee 17. Curysopsis (p. 658). 
Pappus wholly of capillary bristles. 
Rays wanting. 
Involucres narrowly turbinate; bracts arranged in vertical ranks; 
usually shrubs. .......---.-.....- 18. CHRYSOTHAMNUS (p. 660). 
Involucres broadly turbinate or hemispheric; bracts not in vertical 
ranks; herbs. 
Stigma tips obtuse; involucral bracts narrow, slightly imbricated. 
(Rayless species of) 33. Ertazron (p. 674), 
Stigma tips acute; bracts broad or well imbricated or both. 
Leaves with spine-tipped teeth; corolla tube slender. 
(Rayless species of) 19. SmERANTHUS (p. 663). 
Leaves not with spine-tipped teeth; corolla dilated above. 
20. Isocoma (p. 665). 
Rays present. 
Shrub... 22.2.2... eee eee 21, Curysoma (p. 666), 
Herbs. 
Leaves pinnately cleft, or the teeth spine-tipped, or both. 
19. SIDERANTHUS (p. 663). 
