Do you mean it?

Bone blossom was a flower that grew out of a special type of bone called the peculiar bone. 

It was a type of bone left behind by beasts or cultivators with high cultivation. It requires the remains to be left in a humid place that has access to sunlight and rain for many years. And even if all the conditions are fulfilled, it might not grow. 

After the meeting, Lu Mingshu went to look for Qing Mu. "The last time a bone blossom appeared in the heavenly wheel was about three hundred years ago. Daoist priest Hao has been looking for it for years, yet there hasn't been any clue. "

~Right, why would I be able to find it when Daoist priest Hao, who has higher cultivation than me and more connections, is unable to do so?~ "There are still other ways." Qing Mu continued. "Either you see it when you are in the heavenly wheel or meet someone who possesses one."