The terrible earth as it translates... may just be a perfect admixture for preparing changas... irnoicly it has been reported too that Tribulus terrestris will actually grow under illinios bundle flowers.... very interesting indeed.
The idea is that they may not have enough harmalas to actually inhibit orally, but they might be perfect for Smoking.
What we are seeing in smoking of harmalas is that smoked harmalas are much more active then alkaloids consumed orally. This could very well mean that that a simple vodka extract of Tribulus terrestris seeds ie fruit, ie thorns could be used to evap down onto some say mullien and spice and be an effective changa.
Seeds are cheap and due to the fact that this plant is a globally successful invasive species and noxious weed, its well... easy to grow lets just say... it is also popular as an aphrodisiac and for body building. As far as swim understands no one is attempting to smoke this as an Ethanol evaped with spice changa yet.... new territory to explore.
harmalas when smoked go directly to the brain the harmalas in this plant are both MAOI-A&B.
"In chemical terms, it has a very different MAOI profile than either rue or caapi. "The main beta-carboline alkaloids in T. terrestris appear to be harman(e), norharman(e), harmol, and harmalol. Some sources make reference to harmine in the plant, but I haven't found any chemical source to back that claim. I think it may be a case of someone getting harmane and harmine confused in an early publication, and the mistake being reprinted through other sources."~Entropymancer
"The equivalent of 100 mg harmine is 50 mg harmaline, 35 mg tetrahydraharman, 25 mg harmalol or harmol, 4 mg methoxyharmalan. Harmal alkaloids are synergistic (mutually potentiating) and are therefore most effective when combined in an appropriate balance."
https://www.dmt-nexus.me...m=141098&#post141098

There are fairly low amounts of harmalas in the seeds so the seeds would have to be extracted and concentrated much like caapi leaf. A suggested 50X or 50:1 ratio. or 500gms to 1 grams smoked. a kilo of seed would best be soaked and then evaped onto a pile of mullien for smoking.
THe abundance of this herb makes it worth while... as does its names... goats head! caltrop! the terrible earth!