Lichbloom
Lichbloom requires a herbalist to be level 425 to gather and can be found at cold, icy, snowy places such as Storm Peak and Icecrown of Northrend. The collector may even find a Frost Lotus during the process of farming Lichbloom. May need to keep your eyes sharp to find this herb as it can camouflage with the background.
See below for maps to farm Lichbloom in wow.