634 BOTANY OF CROP PLANTS 



inches below the head. The heads are purple and open, 

 early in the morning but usually close by noon. The in- 

 volucre is cylindrical, the bracts nearly equal, in one series, 

 linear-lanceolate, and usually much longer than the rays 

 of the flowers. The corollas (Fig. 260) are truncate and five- 



FiG. 261. — Salsify (Tragopogon porrifolius). Headin fruit; receptacle 

 after having shed the achenes; single achene. 



toothed at the apex. The anthers are sagittate at the base. 

 The style branches are slender. Achenes are linear, and termi- 

 nated by slender beaks, the outer ones being covered with 

 tubercles, particularly on the ribs below. The pappus is 

 grown together at the base, is plumose, and has interwebbed 

 branches (Fig. 261). 



