All of the information displayed on the screen capture you've shown is read-only, and cannot be changed from that screen. It is for informational purposes only.
Normally, only hexes with rules attached to them are identified on the record sheets. So, as you've noticed, Light Woods has Hex Text assigned to it, as do Rough hexes, etc. As stated for the Grass (Decorative) hex graphic, it is intended to be decorative only, usually applied to a non-grass background graphic to show grass areas in the middle of sand or whatever.
Now, while /I/ don't use Grass the way you're suggesting, that doesn't mean that /you/ can't. But it's best to not change the three Standard Palettes (Basic, Intermediate, Advanced) included with the program, as they are used with the included maps. You can easily make aCustom palette, though, and on it, make the Grass hex in question have a Hex Text of Grass if you like.
To do that, simply select the main palette you want to work with (of the 3 standard palettes). For example, if Basic graphics give you everything you want, but you want the added Grass hexes, then start with Basic. (Another reason to use Basic in this particular case is that the current Grass graphic is IN the Basic palette, so it's easier to work with). The steps would be:
* On the Menu, go to Map Options > Palette Management
* Press the Edit Another Palette button
* Select Baisc (or other palette to start with), then Load
* Find the Grass (Decorative) you want to add text to in the Hex Item list using the Terrain Hex Group
* Click on the Clone button, which adds another hex at the end, which is a clone of the Grass hex
* Change its Description to something you'll remember (Grass with Text)
* Most important, enter the Hex Text you want to see when printing into the Hex Text field.
* NOte that the graphics are already included, if you've started with the Basic palette. If you start with anotherpalette, you'll have to copy the graphics you want to the folder you're modifying)
* To save your changes, you can either choose Save Palette As, and give the palette a different name, or Save Palette Changes, which means the Basic palette will be redefined. That would be easier, and shouldn't cause a problem, unless you're trading maps with someone, and they've defined their Basic palette differently. So might be best to make it a Custom one.
Hope this helps.
Whoops, sounds like you already solved your problem. Oh well.