802 



COMPOSITAE (COMPOSITE FAMILY) 



Kays 6 mm. or less long; leaves slightly serrate . . 41. A. Trndeecanti. 

 Rays longer ; leaves entire . . (42) A. panieulatus, v. bellidijlorus. 

 Branches divaricate ; small heads in 1 -sided racemes . 89. A. vimineus. 

 Branches ascending, terminated by solitary heads (39) A. rimineus, v. aascatilia. 

 Rays violet or rose-pink (exceptionally white). 

 Leaves at most 4.5 cm. long, becoming revolute . . 55. A. nemoralix. 



Leaves longer, plane 44. A.junceus. 



V. Involucre more than 5 mm. high Y. 



Y. Bracts with definite firm subulate tips 32. A. polyphyllus. 



Y. Bracts without firm subulate tips Z. 

 Z. Leaves at most 4.5 cm. long. 



Stems many, rigid, from a woody caudex ; bracts firm, the 



inner blunt ; rays blue- violet 52. A. linariifoliux. 



Stem single, from a slender rootstock ; bracts thin, linear- 

 attenuate ; rays rose-pink 55. A. nemoralis. 



Z. Leaves longer a. 



a. Annuals, with inconspicuous rays. 



Bracts definitely imbricated, linear or linear-subulate 

 Bracts subequal, the outer foliaceous. 

 Leaves linear-attenuate ; rays shorter than the style 

 Leaves linear-oblanceolate to spatulate ; rays longer than 



the style 



a. Perennials, with mostly conspicuous rays b. 

 b. Bracts firm, lanceolate. 



Bracts unequal, regularly imbricated, not foliaceous 

 Bracts subequal or imbricat 



b. 



tips 



ited, with spreading foliaceous 



67. A. subulatus. 



58. .1 . angustus. 



59. A.frondosus, 



56. A. Unuifolius. 

 1. A. paludosus. 



38. A. dumosus. 

 43. A. salicifolius. 



Bracts thin, linear or linear-lanceolate. 

 Bracts with conspicuous elliptic or subrhombic green tips. 

 Heads terminating minutely foliose-bracteolate branch- 

 lets 



Heads paniculate, or if few on leafy (not minutely 



foliose-bracteolate) branches 



Bracts without conspicuous colored tips. 

 Rays white ; bracts very narrowly linear-attenuate, 



regularly imbricated, 4-6 mm. long (42) A. paniculatus, v. bellidijlorus. 

 Rays violet or rose-pink ; bracts linear-lanceolate, less 



definitely imbricated, mostly longer . . .44. A.junceus. 

 U. Stem conspicuously pubescent. 



Involucral bracts (or at least the outer ones) bristly-ciliate. 

 Leaves crowded, rigid ; rays white (rarely purple-tinged). 



Heads 5-6 mm. high 36. A. multiflorus. 



Heads 7-9 mm. high 87. A. commutatus. 



Leaves not rigid ; rays blue 85. A. amethyst inn*. 



Involucral bracts not bristly-ciliate. 



Bracts with firm subulate tips ; short rays usually white. 

 Involucre hemispherical or campanulate, as broad as high (33) A. ericoidex, v. 

 Involucre turbinate, narrower than high . . (34) A. dfj><injn>ratus t v. 

 Bracts thin, linear-attenuate, without firm subulate tips ; stem 



puberulent ; long rays violet or rose-pink . . . .55. A.nemoralis. 

 T. Stem-leaves lanceolate or broader c. 



c. Heads in flat-topped corymbs ; rays white or whitish (not blue or violet). 



1, linear-lanceolate ; pappus simple 58. A, pt<tr>n i<-ni<lt . 



pappus double. 

 Involucre 8-4.5 mm. high ; leaves lanceolate to ovate . . .50. A. iintbrllatnx. 



Leaves rigid, linear-lanceolate ; pappus simple 

 Leaves not rigid, broader; pappus double. 



51. A. infirm UK. 



88. A. ericoides. 



Involucre 5-7 mm. high ; leaves obovate to oblong 

 c. Heads paniculate or racemose d. 

 d. Steins glabrous or essentially so e. 

 6. Involucre 5 mm. or less high. 



Bracts with definite firm subulate tips 

 Bracts without firm subulate tips. 

 Heads in more or less 1-sided racemes. 



Leaves narrowly lanceolate, scarcely serrate ; bracts linear- 



attenuate .......... 39. A. riinhi,n*. 



Leaves broader, serrate ; bracts with the midrib dilated 



up ward and rather conspicuous ..... 40. A. lateriflorus. 



Heads on ascending-paniculate branches. 

 Bracts linear-attenuate. 



Heads (including rays) 1-1.5 cm. broad; bracts very 

 slender and fiMfl ....... 



Heads larger; bracts green chiefly at tip . . . . 



Bracts broad-linear or linear-oblong, with conspicuous 

 elliptic or subrhombic rrcen tips ..... 



e. Involucre more than . r > mm. high /. 

 /. Bracts with definite firm subulate tips ..... 



f. Bracts without firm subulate tips g. 

 g. Leaves on branchlets reduced to rigid subulate bracts. 



Perennial; involucre 9 mm. or more high, of firm closely 

 imbricated bluntish bracts ..... ". 



41. A. Tradexcanti. 



42. A. p<micut<i1nx, 



48. A. 



82. A. polyphyUnx. 



% >. A. tnrlintllus. 



