Can the iPhone 4 use 4096 * 4096 textures....

I have a landscape that I want to use a 4096 * 4096 texture on a landscape. Does the iPhone 4 support 4096s? When I set a texture to 4096 in unity it displays black on the iPhone which leads me to think they are not supported by the hardware, if they aren't supported why is that option in there?

Just for the record I'll only be using one huge texture in the scene, the rest will be 64s or 128s.

No. 2048 is the max, with an SGX GPU. The MBXLite only supports 1024.