I'm not sure if ENVI documentation is lousy or just not searchable, but I could not find any good information on how to import ESRI GRID to ENVI ... and the ENVI UI is so unintuitive (hint to ITTVIS, why not just streamline the whole "external file" thing into the same "open image" command used to import geotiffs and the like?) as to make a simple task need explaining!
THIS FUNCTIONALITY IS ONLY AVAILABLE IN THE WIN 32 VERSION!
1. File > Open External File > IP Formats > ESRI GRID
2. Navigate to the hdr.adf within the folder with the same name as the vector you are trying to open and open this