Maple (and Box Elder), Acer spp.
Maple trees are important for honey bees because they offer pollen and nectar while it’s still too cold for many plants — March in central Iowa. I can tell them from a distance by their round oval shape.
While I find maples frequently planted in urban places, Box Elder trees are in the maple family, so I include them here, as I see them frequently in wilder places. This family can be identified with its alternate branches, which you can see in the photos. My children learned these as “buddy branches,” sticking your arms out as if your body was the trunk and their arms were the branches (or large branch and smaller branches).
Many times, we recognize the seeds falling in April (or July or August and later), well after the flowers are finished blooming. We may also recognize them when the leaves change color by their classic shape (thanks, Canada and syrup producers).