Studies of Selected Spermatophytes. 223 



studied to show the range of variations within the family, 

 and on what grounds the members of a family are grouped 

 into genera. Among cultivated plants, hyacinth, tulip, 

 Yucca, and lily, and of wild flowers some species of Allium, 

 Nothoscordum, Polygonatum, and Camassia might be 

 studied. 



Most of the flowers of the lily family allure insects by 

 means of pollen or nectar, or both, and by their fragrance or 

 bright colors. Where the flowers are small, they are often 

 massed in a more or less compact inflorescence for a greater 

 color effect, as in the case of hyacinth and Camassia. 

 Frequently cross pollination is assisted by proterandry or 

 proterogyny. The Yucca is one of the most interesting 

 members of the lily family in the method of its cross polli- 

 nation (see page 196). 



Hypoxis erecta. 



Make diagrams of the flower. In what essential respects 

 does this flower differ from that of Erythronium ? What 

 evidence of relationship do you find ? In what way does 

 the flower bid for insect visits ? Is there any device to 

 prevent self pollination ? Do the anthers stand at the 

 right height to accomplish self pollination ? Do the anthers 

 and stigmas of one flower mature at the same time ? Could 

 self pollination take place in a bud or in a withered flower ? 



Sisyrinchium angustifolium. 



Make conventional diagrams of the flower. Examine 

 both buds and flowers to see whether proterandry or pro- 

 terogyny exists. At what age of the flower do the anthers 

 dehisce ? Can self pollen reach the stigmas at any time 

 while the flower persists? Note how the styles and stigmas 

 change as the flower advances from bud to maturity. 



Make observations in the field to note how long a flower 



