MODIFICATIONS OF THE FLORAL ORGANS. 189 



Fig. 84. Fig. 85. 



This plant is common along the margins of streams and ponds, 

 and may be found in bloom in the month of June. 



Fig. 84, is the stinging nettle, (Urtica,) bearing clusters of 

 greenish inconspicuous unisexual flowers a, in the axils of its 

 leaves. Fig 86, one of the male flowers magnified. Its 

 perianth is a simple calyx of four sepals, within which are four 

 stamens opposite to the sepals, situated on the receptacle, and 



17 



