A fifth Great Tree can be found in Crystalsong Forest[13, 34] on the continent of Northrend. The only non-crystal in the entire forest, this enormous tree stands near its western edge. Few trees are even close to this one's size — its trunk is easily as thick around as a castle and its canopy rises several hundred feet above the ground. Its roots must be equally deep to pass below the crystals into soil, unless the crystals themselves provide nourishment.
Great Trees are portals into the Emerald Dream. Twelve green dragons guard it constantly, nesting in its branches and swooping down to intercept visitors. Druids are allowed entrance. Everyone else is turned back, or killed.LoM 98
In World of Warcraft: Wrath of the Lich King, it is no longer the only non-crystal tree in the entire forest, as only the eastern half of the zone and the Azure Front are crystalized. Unlike the other four Great Trees, this Great Tree does not have a portal in front of it, and has strange runes dotting its surface. The Tree serves no current use.