My cacti just arrived. I was under the impression it was going to be a 7 pointed star when cut in half. If this is not SP what is it? Does it contain any Alkaloids?

It is san pedro.

Now why were you waiting a 7-pointed star? san pedro can have 4+ ribs, yours has five. Were you told that you'll be getting a 7-ribbed one?

I'm sure theres some alks in there, but the real question is how much.

It takes alot of catus to get a good dose. I recommend starting with a section about the length of your forearm.

I don't think the number of ribs makes a difference. Some say the four rib is more potent. But most four rib cacti I've seen end up adding a rib at some point.

I even have a cactus with no ribs....its called a TBM or "Penis Plant"

was it shipped w/such a fresh cut? or did you cut it upon arrival?

be sure to let it callous for a few weeks before planting

It certainly looks like Pedro. Good Luck

Looks like someone ripped it out instead of cutting with a knife. Make sure u cut that part off if u want it to root faster.

Thanks

After pureeing it's been reduced down to ~400ml. It has just the right consistency to add enough lime to do a dry tek.

Looks like the shape of bridgesii but the spines sure dont look like bridgesii, hmm. Albert would probably know. San Pedro is actually the generic name for several different species of cacti.