Morrowgrain

Morrowgrain, under the right conditions, exude qualities like other herbs used in primitive curses. , Archdruid and Archdruid  are interested in its qualities.

Source
Obtained by using the on two piles of  and a. The resulting will provide either Morrowgrain or  when opened.

Morrowgrain research
Fandral Staghelm in Darnassus and Hamuul Runetotem in Thunder Bluff, archdruids of the Cenarion Circle, are investigating the properties of when grown in  from Un'Goro Crater.

When the character responds to the archdruid's call for aid, they are first asked to bring a number of samples of the soil of Un'Goro back to an assistant. The archdruid then explains their program for researching Morrowgrain, which they know little about. By growing Morrowgrain for the Cenarion Circle, the character is given a bag of various goodies - food, water, some potions and elixirs. And the need of the circle for more morrowgrain for research is endless - provide them more, and they will give more of these goody bags.

Not all of the Circle trust Staghelm, though. at Feathermoon Stronghold has also expressed interest in doing independent Morrowgrain research, although only members of the Alliance are able to talk to him without starting a fight.

Imprisonment of Malfurion Stormrage
After the Lich King's defeat, Staghelm's purpose for the Morrowgrain was revealed: he was using it on to trap him in the Emerald Nightmare and, eventually, to kill him. The healing power of Elune, as channeled through the priestesses caring for Malfurion, kept him alive until he was able to escape the Nightmare and expel the poison from his body.