Aaron's beard may refer to the following plants having numerous stamens or threadlike runners: The name derives from a Biblical quotation referring to the patriarch Aaron: "Behold, how good and how pleasant it is for brethren to dwell together in unity!
It is like the precious ointment upon the head, that ran down upon the beard, even Aaron's beard: that went down to the skirts of his garments"-- Psalm 133:1-2 (King James Version)