AMERICAN HONEY PLANTS 



243 



honeydew, and, as it came ahead of the clover flow, was probably nearly all 

 consumed for brood rearing. 



For a time the writer was puzzled to know whether the bees were 

 getting an exudation of sap from the tree, or were in fact getting honey- 

 dew. They were working on what appeared at first sight to be buds at the 

 base of the new growth, but which under the microscope proved to be in- 

 sects identified as Physokermes picea. 



SPURGE, see Snow-on-the-Mountain. 



Fig. K 



Yellow star thistle. 



SQUASH (Curcurbita maxim), also (C. moschata). 



Squashes are widely cultivated for food. There are numerous varie- 

 ties, but all are valuable sources of pollen and nectar. They secrete nectar 

 freely, and where sufificiently abundant, a considerable quantity of honey 

 is stored. 



STAR THISTLE or KNAPWEED (Centaurea). BARNABY'S THISTLE. 



There are several species of star thistles or knapweeds widely dis- 

 tributed. The yellow star thistle (Centaurea solstitialis) (Fig. 131) is an 

 introduced species from Europe that occurs from Massachusetts and On- 

 tario, west to Iowa. It is also common in parts of California. It is only 

 from the latter State that it is reported as an important honey plant. 

 According to C. D. Stuart (American Bee Journal, page 340, October, 1918), 



