802 



COMPOSITAE (COMPOSITE FAMILY) 



Eays 6 mm. or less long- ; leaves slightly serrate . . 41. A. Tradescanti. 

 Rays longer ; leaves entire . . (42) A. paniculatus, v. bellidiflorus 

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

 Branches ascending, terminated by solitary heads (39) A. vimineus, v. saxatilis- 

 Rays violet or rose-pink (exceptionally white). 



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

 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 



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

 attenuate ; rays rose-pink 

 Z. Leaves longer a. 



52. A. linariifolius. 

 . 55. A. nemoralis. 



57. A. subulatus. 



58. A. angustus. 



59. A.frondosus. 



56. A. tenuifolius. 

 1. A.paludosus. 



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. 

 &. Bracts firm, lanceolate. 



Bracts unequal, regularly imbricated, not foliaceous 

 Bracts subequal or imbricated, with spreading foliaceous 



tips 



6. Bracts thin, linear or linear-lanceolate. 



Bracts with conspicuous elliptic or subrhombic green tips. 

 Heads terminating minutely foliose-bracteolate branch- 

 lets 38. A. dumosus. 



Heads paniculate, or if few on leafy (not minutely 



foliose-bracteolate) branches 



Bracts without conspicuous colored tips. 



Eays white ; bracts very narrowly linear-attenuate, 



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

 Eays 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 37. A. commutatus. 



Leaves not rigid ; rays blue 35. A. amethystinus. 



Involucral bracts not bristly-ciliate. 



Bracts with firm subulate tips ; short rays usually white. 



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

 Involucre turbinate, narrower than high . . (84) A. depauperatus, \.parviceps. 



43. A. salicifolius. 



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



puberulent; long rays violet or rose-pink 

 T. Stem-leaves lanceolate or broader c. 



55. A. nemoralis. 



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

 Leaves rigid, linear-lanceolate ; pappus simple 



53. A. ptarmicoides. 



Leaves not rigid, broader ; pappus double. 

 Involucre 3-4.5 mm. high ; leaves lanceolate to ovate . . .50. A. umbellatus. 

 Involucre 5-7 mm. high ; leaves obovate to oblong . . .51. A. infirmus 

 Heads paniculate or racemose d. 

 d. Sterns glabrous or essentially so e. 

 6. Involucre 5 mm. or less high. 



Bracts with definite firm subulate tips 33. A. ericoicfes. 



Bracts without firm subulate tips. 

 Heads in more or less 1-sided racemes. 



Leaves narrowly lanceolate, scarcely serrate ; bracts linear- 

 attenuate 39. A. vimineus. 



Leaves broader, serrate ; bracts with the midrib dilated 



upward 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 green 41. A. Tradescanti. 



Heads larger ; bracts green chiefly at tip . . . . 42. A. paniculatus. 

 Bracts broad-linear or linear-oblong, with conspicuous 



elliptic or subrhombic green tips 43. A. salicifolius. 



. Involucre more than 5 mm. high /. 



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



f. Bracts without firm subulate tips g. 

 g. Leaves on branchlets reduced to rigid subulate tracts. 



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



imbricated bluntish bracts . 28. A. turbinellus. 



