I do not know much about ethnobotany, but one expereince I had while working under a Cedar Tree for three months has convinced me that plants have definite influence over our lives, an amazing healing ability and "magic" even.
Each ecosystem has a power that influences the people there. For example, the rainy forests on the Pacific Northwest are mellow and cool and calming, there is immense magic in these forests and mountains. The forests of the East have a different feel. Many being barren and woody(due to overharvesting) and walking into them feels like a graveyard at times. This Sonoran desert of the Southwest is something completely new to me. It is interesting to me to compare the different cultures, both modern and ancient and see the immense influence of the environment.
My first morning here, I heard fighter jets and saw many airplanes. I think that even if there weren't numerous airforce bases out here, this place would still have a lot of mystery around it, maybe still speculation about UFO's. There is such an immensity to the land and an unsettling quietness, lending itself to opening up the mind to possiblities of other realms.
The picture below is of one of the mystical agave plants, which among the cactii(wonderful survivros) populate this desert landsacape.