Iris lacustris
 
 
  
Figure 2.
Left:  Iris lacustris under cultivation in the W. J. Beal Botanical Garden.
Middle:  Iris lacustris blooming in May in situ, shaded by Thuja occidentalis. (photo provided by The Nature Conservancy, Michigan Field Office)
Right:  Close-up of Iris lacustris flower. (photo provided by The Nature Conservancy, Michigan Field Office)