Call up the city Dep't that planted it and tell them your worries. They may have a program in place to deal with EAB. If nothing else, they should be able to inspect it. Also, if the area in which the tree is planted is in a bit of a hollow, it may be in a frost pocket, and have had a hard freeze even as its neighbors had a light one. It may also be in an area of soil that either drains especially well or especially badly, compared to the other trees, so is getting less or more water than they are. Neither of these sound too likely, since you say whole branches aren't leafing out.

sounds like it could be a cross to me too; here's an interesting one: http://users.kymp.net/citruspages/limes.html#merdeka update: also found out that the papeda family all have the double leaf! so it could be a yuzu (which purportedly also have scented leaves) or perhaps a khasi papeda (which supposedly looks just like a makrut but has more edible fruit!). i sometimes buy ponzu made with yuzu (the good stuff is made this way) and have seen yuzu trees sometimes in stock at the local home depot; might have to try one! the khasi is also super intriguing; although seems really rare. This post was edited by farm96744 on Mon, Mar 3, 14 at 16:09

I just realized that I spelled that incorrectly. Only after making the same mistake and correcting it on another reply. Is there any way to correct the title for future searches?

If you had verticillium wilt, you would know it!! There is no mistaking the very rapid effect of that pathogen. Red maples (Acer rubrum), which is what you have, are very tolerant of a wide range of soil pH, more so than any other maple species. Your soils must be quite alkaline to result in that degree of chlorosis. You can address with a chelated iron product but that is only a temporary fix. Adjusting a high pH soil is a difficult thing to accomplish.