82 



Common Borage. The blue flowers of Borrago offi- 

 cialis iire commonly visited by honey bees which seek the 

 neotar that is abxindantly secreted by the pale yellow fleshy 

 part at the base of the ovary. The anthers meet to form a 

 cone. 



Mertensia Virginica DC . Blue Bells are conspicuous 

 in deep, rich woods. The blue, trumpet-shaped corolla has 

 a spieading limb; the slender filament are exserted. An 

 abundance of nectar is seci-eted by four glands at the base of 

 the ovary which alternate with the base of the carpels. Mr. 

 Robertson says: "The blue color and the size of the tube, 

 together with the pendulous position of the flowers, indicate 

 an adaptation to the larger bees, but butterflies sometimes 

 hang on the flowers and draw out their honey. In the fol- 

 lowing list all the insects are intruders except Bombus, 

 Anthophora-, and SynJialoniar 



Plants of this order are not abundant in 



Cotivolvulaceae. -, »» ^ u j i. • ^l 



lowa. Most abundant is the common 



(Morning Glory Convolvulus sepium.) The flowers are 

 large and white. It is without odor Hor has it any path-find- 

 ers. It opens during the early morning and is not abund- 

 antly visited by insects. Hermann Mueller states that on 

 dark evenings he found it closed between 9 and 10 o'clock, 

 but open on moonlight evenings. Its distribution in Europe 

 is supposed to be.dependant on Sphinx ConvolvuU but Muel- 

 ler records a number of other visitors and Robertson reports 

 a number of Apidae. 



The C. arvensis has become a common weed in places. 

 It has a funnel-shaped, white or red corolla with a yellow 

 base on the inside and five radiating white streaks which are 

 the path-finders. The flower closes in the evening and rainy 

 weather and is therefore adapted to diurnal insects. 



