porkpal said: Are there other trees that yield sugary sap?
porkpal said: Terrific! What is it?
ViburnumValley said: You can post as many pictures as you can take. Show us more.
When you collect a branch, go ahead and photo the entire thing, and then do the closeups of various parts. It also helps sometimes to include something for scale in the image, like a coin or another common item which is recognizable.
Those buds really look like Acer platanoides to me. Norway Maple buds are fat, usually greenish/purplish in winter, and have the large bud scales as seen in your photo.
Use a white background on the next go-round, too, so that the plant's colors are more prominent.
The big old tree (now gone, due to inconsiderate airport management) was a fine Acer rubrum - which I provided for comparison to bark characteristics and habit.
If you wait around for the next flowering/fruiting period, you'll see the distinctive pairs of samaras - which is ANOTHER great way to separate different species of maple. The size of the seed and the angle between the two ends of the pair can be definitive.