Cultivated-Plant Study 



627 



Iris in btossom. 

 Photo by Verne Morton. 



its purple and yellow tip and many guiding lines although far from the 

 center of the flower, is the sure path to the nectar, A bee alights on the 

 lip of the sepal, presses forward scraping her back against the down- 

 hanging stigma, then scrapes along the open anther which lies along the 

 roof of the tunnel; and she here finds a pair of guiding lines each leading 

 to a nectar-well at the very base of the sepal. The bees which Dr. Need- 

 ham found doing the greatest work as pollen-carriers were small solitary 

 bees (Clisodon terminalis and Osmia destructa) ; each of these alighted 

 with precision on the threshhold of the side door, pushed its way in, got 

 the nectar from both wells, came out and sought another side door 

 speedily. One might ask why the bee in coming out did not deposit the 

 pollen from its own anther upon the stigma; but the stigma avoids this 

 by hanging down, like a flap to a tent, above the entrance, and its sur- 

 face for receiving pollen is directed so that it gathers pollen from the 

 entering bee and turns its back to the bee that is just making its exit. 



The arrangement of the flower parts of the iris may be described 

 briefly thus: three petals, three sepals, a style with three branches; the 

 latter being broad and flat and covering the bases of the three sepals, 

 making tubes which lead to the nectar; three anthers lie along the 

 under side of the styles. The wild yellow iris is especially fitted for 

 welcoming the bumblebee as a pollen-carrier, since the door between 

 the style and the sepal is large enough to admit this larger insect. 

 The bumblebees and the honey-bees work in the different varieties 

 of iris in gardens. 



