Refers to the chaparral yucca, small variety that grows close to the ground.
In Mesa Grande dictionary, 'aakuull refers specifically to the flower stalk, whereas the yucca plant with no stalk is called 'emaa. When referring to yucca in general, however, 'aakuull may be used, as seen in "Mountain" by Ted Couro. Most dialects appear to simply refer to yucca as 'aakuull.