Sumac, Rhus
According to NREM at Iowa State University, Smooth (Rhus Glabra) and Staghorn Sumacs (Rhus typhina) are native to Iowa.
Their flowers are difficult to spot because of their size and color, so I look for them in the fall when I see red seedheads and red leaves appear. The relation to beekeeping is the dried fruit heads can be used as smoker fuel.