Descriptive Flora 



211 



Page 



base Chaetopappa — 221 



2. Plant 1 — 4' high, branch- 

 ed above Aster — 221-2 



(2) Flowers over y 2 " across. 



o. Heads on naked stalks Melampodium — 226 



p. Heads not on naked 



stalks Aster— 221-2 



4. Rays about 50. 



1. Leaf-blades entire Erigeron — 223 



2. Blades not all entire Aphanostephus — 220 



(b) Strap-shaped ray flowers none 



(Outer disk flowers often en- 

 larged). 



1. Flowers large, 2 — 4" across Centaurea — 242 



2. Flowers less than 2" across, 

 (m) Shrub, leaves linear, dot- 

 ted with resin Baccharis — 224 



(n) Plants not shrubs, 

 r. Leaves deeply segmented Hymenopappus — 236 

 s. Leaves not deeply seg- 

 mented, 

 (x) Flowers snowy, about 



1" across Marshallia — 235 



(y) Flowers less than 1" 

 across. 



(1) Leaves linear Kuhnia— 216 



( 2 ) Leaves broader than 



linear Coleosanthus — 216 



d. Flowers blue to purple. 



1. Sap milky — Lygodesmia — 245 



2. Sap not milky. 



(a) Plant prickly. 



1. Leaves white-woolly under- 



neath Cirsium — 242 



2. Leaves not white-woolly under- 



neath . . Perezia — 243 



(b) Plant not prickly. 



m. Leaves all basal ,T. Gaillardia — 239 



n. Leaves not all basal, 

 r. Ray flowers strap-shaped. 

 (1) Basal leaves about 1" 



