I spent all day yesterday glued to the computer, searching out the history of coleus as a possible ethnogen. The literature I reviewed mentioned their use together in contemporary accounts, but it called into question the
ancient use of coleus and S. divinorum in Mexico, as the natives were not using them to their utmost advantage, as if they were not really that familiar with the plants. There was a broad "hint" that the plants were cultivars introduced from somewhere else, but when, where and by whom is apparently a mystery.
According to the internet, there are two kinds of coleus: the colorful ones and the green ones (which may or may not actually be coleus). This may account for the lack of consistency/potency in coleus trials. They both apparently have the potential for containing ethnogens, but the green ones win out in traditional uses.
The major "green" coleus, Coleus (Plectranthus)Amboinicus, also called Cuban Oregano or Indian Borage, is used as a medicinal herb in India, called Pashnabhedi,and is considered an ethnogen there.
The colorful varieties have been hybridized by plant breeders for centuries, looking for interesting color combinations, and that could account for the lack of potency or conflicting information there. My search for "heritage" plants (the original breeding stock) which might still have the reported potency turned up some varities claiming to go back to Victorian times, but no mention of traditional ethnogenic uses.
I guess my question now is, anyone tried Cuban Oregano?
"Hang in there. The light only comes at the END of the tunnel." [i]Letters to Oso, 2010