Why is California mugwort (Artemisia douglasiana) also known as Dream Sage?

Chumash healers use Dream Sage, or molush, to help those having trouble dreaming, which they believe can lead to depression and general ill health. Dried sage is sewed into a small packet to place beneath the patient’s pillow. The plant contains many complex, fragrant compounds which the Chumash believe help heal the spirit by inducing vivid dreams. (1)

FOOTNOTES
(1) https://pmc.ncbi.nlm.nih.gov/articles/PMC1062165/#:~:text=Dreams