This is just one chapter from Dale Pendells impressing trilogy: Pharmako Poeia, Pharmako Gnosis and Pharmako Dynamis. These books are not public domain text, but the chapter on Salvia Divinorum from Pharmako/Poeia: Plant Powers, Poisons, and Herbcraft are available for free. The works have an interesting way of approaching the plant world from more angles. The chemistry is explained, the botany and pharmacology are combined with alchemy, history, sociology and comments from the Ally, the plant itself:
Sometimes the sage whispers, sometimes it shouts. Sometimes it tells you to sing, sometimes it takes your voice, walks off, leaving you
rooted, eyeless, and with the kind of voice a plant has.
The books can be bought on Daniel Sieberts website SageWisdom.com: – I did that.
You can download the chapter on Salvia Divinorum here: