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5, Troximon.—Pappus capillary. Bristles 
deciduous singly, not in a ring. Apex 
of akenes rostrate; costs smooth. 
6. Taraxacum.—Pappus capillary. Bristles 
persistent, Apex of akenes elongated, 
rostrate; coste roughened. 
7. Sonchus.—Akenes flattened, not ros- 
trate. Pappus silky, white, 
8. Hieracium.—Akenes terete, not rostrate, 
Pappus brittle, discolored. 
B. Flowers tubular. 
a. Leceptale naked. 
aa, Branches of the style club-shaped. 
1. Adenostyles. — Involucre 1-seriate. 
Branches of the style filiform. Pappus 
copious, silky, white. 
2. Bulbostylis.—Involucre imbricate, 2-3 
seriate. Branches of the style filiform. 
Pappus copious, silky. 
bb. Branches of the style flat and tipped 
with an appendix. 
aaa. Parts of pappus o. 
1. Bigelovia.—Involucre imbricate. Pap- 
pus l-seriate, capillary, brownish at ma- 
turity. 
