I could find very little information on the Ariocarpus sp. on this forum so I though I would start a workspace getting the ball rolling with some of my research. Please don’t hesitate to add anything you can find, or correct any of my research if you believe it is out of date.

As a quick introduction Ariocarpus is a genus of psychoactive cacti. They do not contain mescaline like they’re much better documented counterpart peyote. Their main active constituent is Hordenine [1]. In addition to this they contain many other psychoactive chemicals in lesser amounts. Their habitat is restricted to the chihuahuan deserts [1]. They may be referred to as false peyote, living rock, or star cactus [1]. Some saying they provide even stronger trips than peyote cacti.

I think it is important to also highlight the endangered conservation status of these cacti. I cannot condone collecting the endangered species in the wild, especially considering that illegal collecting is the main threat of these cacti. I hope that as a community we can increase the knowledge and conservation effort about these plants without increasing illegal demand.

See below for a summary of what I have found on the different species so far:

Ariocarpus agavoides
-Conservation status: Endangered (population decreasing) [2]
-Illegal collecting is main threat [2]
-Known psychoactive chemicals: Hordenine, N,N-dimethyl-4-hydroxy-3-methoxyphenethylamine, , N-methyl-3,4-dimethoxyphenethylamine [1]
-Alkaloid composition over 50% Hordenine, 1-10% N,N-dimethyl-4-hydroxy-3-methoxyphenethylamine, trace amounts , N-methyl-3,4-dimethoxyphenethylamine [3]
-AKA magueyitos (little agaves) [3]

Ariocarpus bravoanus
-Conservation status: Endangered & Decreasing [2]
-Endangered due to over collecting [2]


Ariocarpus fissuratus
-Conservation status: Least concern [2]
-May be called Roseocactus fissuratus, peyote cimarrón, chaute, Sunami [1], and hikuli sunami [4]
-Known psychoactive chemicals: Hordenine, N-methyltyramine, N-methyl-3,4-dimethoxyphenethylamine [1]
-Tarahumara assert that it is ‘stronger than true peyote [1]
-consume fresh or crushed and served as stimulant to runners [1]

Ariocarpus kotschoubeyanus
-Conservation status: Near threatened (Population decreasing) [2]
-Illegal collecting is a threat [2]
- Known psychoactive chemicals: Hordenine, N-methyltyramine [1]

Ariocarpus retusus
-Conservation status: Least concern (stable) [2]
-AKA Tsuwiri [4], chaute [1]
-Huichol consider A. retusus a false peyote and that it is ‘evil,’ driving you mad in the desert if you are not in a state of ritual purity that allows you to find the true peyote [4]
- Known psychoactive chemicals: Hordenine, N-methyltyramine, N-methyl-3,4-dimethoxyphenethylamine, & N-methyl-4-methoxyphenethylamine. [1]

Ariocarpus scaphirostris
-Conservation status: Endangered (Population decreasing) [2]
-Illegal collecting is a main threat [2]
- Known psychoactive chemicals: Hordenine, N-methyltyramine, N-methyl-3,4-dimethoxyphenethylamine, N,N-dimethyl-3,4- dimethoxyphenethylamine. [1]


Ariocarpus trigonus
-Conservation status: Least concern (stable) [2]
- Known psychoactive chemicals: Hordenine, N-methyl-3,4-dimethoxyphenethylamine [1]



Sources
[1] Richard Evans Schultes, The Botany and Chemistry Of Hallucinogens. Springfield, Illinois, USA: Charles C Thomas, 1980.
[2] ICUN. (2019, May) ICUN Red List. [Online]. https://www.iucnredlist.org
[3] JAN G. BRUH & CATARINA BRUHN, "Alkaloids and Ethnobotany of Mexican Peyote Cacti and Related Species," Economic Botany, vol. 27, April-June 1973.
[4] Richard Shultes, A Golden Guide Hallucinogenic Plants. Racine , Wisconsin , USA: Golden Press, 1976.

I could be mistaken, but I thought I read in the Phalaris section that hordenine is one of the toxic things you didn’t want to pull, along with gramine.

Not too familiar with phalaris extraction, but this: http://herbpedia.wikidot.com/hordenine suggests that it is somewhat toxic. There seems to be very little information on the LD50 that links suggests 2000 mg for dogs, comparing that to active doses for humans it seems to be more toxic than many of the psychedelics that are commonly discussed here. Interestingly it also says that its primarily a stimulant. It would be interesting to see how big an influence the other phenethylamines in ariocarpus have on the experience even though they occur in relatively low doses.

For what its worth hordenine is also in peyote, and I haven't heard of problems there. There is definitely very limited information on these compounds so it is hard to say anything very conclusive about it's safety.