Yeah, this is absolutely an area we should work on, and I am as you know currently working on it. I'm interested in sending samples of extracts to anyone with the equipment to properly identify the substances in the extract. But I want to clarify a few things: The
Radula genus are not lichens, they are liverworts. They are indeed active, but as they are very small in growth, you need to find a big population of them. The active cannabinoids can be extracted by any non-polar solvent, or by fat, just as THC.
Around a gram should be the threshold dose: My experience with extract of 2 grams of
Radula complanata was rather potent. Assuming the reported concentration of 0.56% perrottetinene from
Radula marginata can be applied to
Radula complanata, I smoked maybe 11 mg perrottetinene. As perrottetinene has
cis instead of
trans stereochemistry, one should expect maybe half the potency of THC. The added phenyl ring should not make much of a difference in terms of potency, as the chain it is attached to is too short. Following this logic, ~5 mg (~1 gram herb) should be a threshold dose. For THC the threshold dose for intoxication is around 2-3 mg, so this correlates ok. Note that these numbers and this logic is theoretical, but it adds up.
When it comes to lichens, we are talking about something different. I think the substances found in lichens are unlikely to be active at cannabinoid receptors, but they are indeed active. I did a warm water extract of
Parmelia conspersa, and that was active, but I don't feel it as a cannabinoid. Usnic acid and the other "lichen acids" are thought about as not water soluble, so they should not have followed through in my extract, which means that other substances may be responsible for the effects. I used hot water, however, which should increase solubility, so maybe the lichen acids followed through. I'm about to do a cold water extraction on
Parmelia conspersa to test this.
So we have liverworts with cannabinoids and lichens with unknown actives. We also have many other different lichens and liverworts that are active, look at
this list I made and the posts that is following it. Sorry if I'm unclear or something in this post, I smoked some
Lycopodium clavatum and feel a bit off. It's been a long and hard day. Oh, and that's a new type of active small plants - the clubmosses. So we have lichens, liverworts, and clubmosses. I'm betting we will find active moss too.