Dreaming Glory requires a herbalist to be level 315 to gather and is widely spread and can be found everywhere in the Outlands. It is generally found on cliff edges and on top of peaks. Just like Wild Steelblossom or Mountain Silversage they can be difficult to reach. The herbalist will receive a 15 minute buff that heal 30 HP every 5 seconds by collecting a Dreaming Glory and will restart whenever another one is collected.
See below for routes to farm Dreaming Glory and get the buff.