In beginning times plants like animals were human and still retain these qualities hidden in leafy form. They are thus no less animate, no less closely related to us than say a spider monkey might be. One reason that we don't notice this is that their sleep cycle is opposite our own. Trees and other plants sleep during the day and come awake at night when we are dreaming. It is for this reason that they appear active and humanlike in dreams. For example, when sick person ingests medicinal bark it triggers a healing relation to the tree that only becomes visible at night. That night, when the tree wakes up, it comes to the patient in a dream as a human doctor come to treat her ailment.