Tried doing this quest many many many times I did. For awhile people thought that the foraged plains pebble from the Karana's and a water reed foraged from Ill Omen were the components needed to combine.
Alas twas not ta be. There are many many threads on the druids grove prolly quite a few pages back now though.
Nobody has figured out what to put in there, and it seems many druids have tried just about every combination of junk to put in there to combine.

~Jaelen Thornberry~
Adorable lookin', liquer swillin', funny talkin', feisty Priestess of Mother