109 



YuGOa- The glorious yuccas are native American plants 

 occurring most commonly in the dry, sandy regions of the 

 southwest. Spanish diagger or Spanish bayonet {Yucca 

 uwgustifolm) occurs in the loess region oti the Missouri river 

 in the western part of Iowa. Drs. C. T. Riley and George 

 Engleman have made some interesting and valuable observa- 

 tions on the method of pollination in this spedes. Prof. 

 Trelease and Mr. Webber have substantiated their work. In 

 Yuccas the relation between the flower and a yucca moth is 

 very close. The pendant, more or less bell shaped flowers 

 are borne in mostly simple racemes having a perianth of three 

 sepals and three petals, yellowish white in color and very 

 fragrant. Both color and odor make them conspicuous for 



FIG. 46. 

 Vie. Hi- Moth collecting pollen. (After Riley) . 



night-flying insects. The viscid pollen is contained in small 

 anthers which arise from the papillose, curved filaments. A 



