THE FLOWER AND THE BEE 



of bee. But in late September, after the autumnal honey-flow 

 from the goldenrods was over, I repeatedly saw honey-bees 

 examine the blossoms, but they made no attempt to depress 

 the keel. None of their efforts to find the nectar proved 

 effectual. Neither are the bumblebees more successful. But 

 I have seen a queen of Bomhus fervidus visit twenty flowers in 

 succession, and obtain the nectar illegitimately through a crevice 

 between the standard and a wing-petal. Until the summer 

 of 1912 I did not suppose that there was a single species of our 

 native bees which could pollinate the flowers. But in Septem- 

 ber a female leaf -cutting bee {Megachile latimaniis), a large 

 and powerful insect, put in an appearance. She easily de- 

 pressed the keel and, thrusting her tongue beneath the stand- 

 ard into the staminal tube, sucked the nectar for a long time. 

 She was so fearless that I was able to stroke her back 

 with my finger. As the flowers of the sweet pea are easily 

 self -pollinated, they are very prolific, even in the absence of 

 insects. 



Another species belonging to the pea family, which is also 

 pollinated chiefly by leaf-cutting bees, is alfalfa, the most im- 

 portant of fodder-plants in the West, and a most valuable 

 source of honey to beekeepers. The flowers are known as ex- 

 plosive flowers. The anthers and stigma are held in the keel 

 imder tension. When a bee presses down the wings and keel, 

 it has been described as pulling two triggers and firing off the 

 flower, that is, the anthers and stigma fly forcibly upward and 

 the pollen is thrown against the body of the bee. Three leaf- 

 cutting bees {Megachile latimanus) have been observed to trip 

 the flowers at the rate of 55^^ per hour. Honey-bees make a 

 practice of stealing the nectar through a hole in the side of the 

 corolla, but are of little benefit as pollinators. East of the 

 Mississippi alfalfa yields very little nectar, but in the Western 



