View a petiole.

Oak {Quercus sp.};  bears acorns- the “nut with a hat”

Maple {Acer sp.}, Sycamore {Platanus sp.}, OR Similar-Shaped Leaves

Arrowhead-Shaped Leaves

Serrated Edges (toothed like a saw blade OR similar) / Smooth Edges

Spade-Shaped Leaves

Serrated Edges / Smooth Edges

Lance-Shaped Leaves

Serrated Edges / Smooth Edges

 

 Sources:  

Wikipedia on Maple:  http://en.wikipedia.org/wiki/Maple

Photos for {Acer sp.) from Sugar Maple profile on USDA.gov:  http://plants.usda.gov/core/profile?symbol=ACSA3

Other Photos & Database Entry: Distance Everheart 10-24-14