BPotD work-learn student Cora den Hartigh is the author of today's entry. She writes:
Dictyonema huaorani is a lichen I have been researching quite a lot this semester. For a directed studies project, I chose to investigate hallucinogenic lichens--a hybrid between popular lichenology and scientific enquiry. It was a lot more difficult than anticipated, but I finally turned in a short book, over a week late! That's just how it goes sometimes. Nevertheless, I contacted Michaela Schmull at the Harvard Herbarium, who was able to forward me this magnificent scan. Now I can share the story here!
This is a scan of the thallus, or vegetative structure, of Dictyonema huaorani. This specimen was collected in 1981 by Wade Davis and Jim Yost, two explorers in eastern Amazonian Ecuador conducting ethnobotanical research with the Waorani people. Yost had heard rumours of this lichen for seven years before finally locating this individual. To date, this is still the only known specimen in existence. As you can see by the label, this lichen was found growing on rotting wood near the confluence of the Quiwado and Tiwaneo rivers in Napo state. Known as nɇnɇndapɇ by the Waorani, the lichen has been used by "bad" shamans to curse others and also been noted to cause severe headaches. It was reputed to potentially have hallucinogenic properties.
The unidentified specimen was forwarded to Dr. Mason Hale, who suggested that it might be a species of Dictyonema, perhaps similar to Dictyonema sericeum. A conclusive identification would not be made for another forty years--this past November! A team of scientists sampled the specimen's DNA and found it to be an as-yet unrecognized species, which they named Dictyonema huaorani. Even more fascinating, they were able tentatively ascertain the presence of psychoactive compounds: tryptamines and psilocybin. Psilocybin is notably found in the infamous Psilocybe cubensis (though also in least 200 other species of fungi), but this is one of the first publications indicating psychoactive compounds in lichens!
Although no fresh material is available, the dried specimen hints at how stunning and ethereal this lichen might look. You can also get a good idea by taking a peek at some similar species, of which there are many! Just recently, a molecular study of Dictyonema glabratum revealed the taxon could be split into at least 126 different species. They make for a lovely colour palette!
Lichens are the result of a sort of pact struck between a fungus and something that can photosynthesize, usually an alga. Because the fungus (or mycobiont) cannot produce its own food, it relies on its photobiont partner for sugars. Algae, on the other hand, have a hard time taking up water and staying hydrated. A lichen forms when a compatible alga and fungus team up (see illustrations). The fungus will form a thick protective layer of hyphae called the cortex. Beneath the cortex is a layer of algal cells, photosynthesizing away, suspended above a loose mesh of more hyphae called the medulla. In some lichens, particularly foliose or fruticose ones, a lower protective cortex is formed below the medulla. This is not always the case, though. There are the jelly lichens, which are a jumble of photobiont and mycobiont without any sort of stratification, or lichens with photobiont packed together in cephalodia. Crustose lichens never have a lower cortex: instead, they fuse directly to their substrate. Some lichens are even able to re-assemble themselves in a few months if turned upside-down, moving all of the algae through the medullary layer to face the opposite cortex where they will be exposed to more light.
The lichen complex has been observed primarily among fungi in the Ascomycota, but about 1% of lichens have a basidiomycete as the mycobiont. The photobiont, too, can be a cyanobacterium instead of an algae. This occurs in roughly 10% of all lichens. Dictyonema is particularly bizarre because it is a basidiolichen teamed up with a species of Scytonema, a cyanobacterium!
You can read more about lichens via Lichens of North America or the delightful Ways of Enlichenment.