Even without leaves, maples are very busy this time of year. Look at the ends of the branches on this maple tree below: there are lumps all along the branches.
|Swollen maple buds ready to pop. Early March.|
Those lumps are flower buds. Many maples flower and fruit before they leaf out. Here is a closeup of maple flowers:
|Mid March, maple flowers.|
Either way, lots of pollination has happened, because the maples in Chicago are LOADED with maple fruit. Notice I called these helicopter things seeds earlier in the post, and now I'm calling them fruit. I didn't want to alarm you earlier, but here's how this works: fruits are plant parts that hold seeds. An apple fruit has seeds in it, and so does a cucumber, and so does a maple fruit. The maple fruit consists of a wing and a case around the actual seed. Open up the swollen end of the fruit, and you will find a sticky seed (and you can stick the fruit on your nose or fingers like we did when we were kids).
|Maple fruits (samaras) in late March.|
|New (red!) maple leaves, plus some maple samaras, late March.|
|Japanese maple leaf buds opened and showing the new expanding leaves, late March.|
|Slightly older Japanese maple leaves, late March.|