Can someone point me to something scientific concerning the origin of euphorbia "trigona". Ive read its a hybrid and that it never blooms. Ive been wondering about it for a while now....
Mostly about its parent plants.....

I remember something about this in the Euphorbia journal books. When I have time I'll try to dig in and see where it was. By the way Stefan, you should check out that series if you can get your hands on any of the volumes, lots of interesting stuff about succulent Euphorbias, including origins.

I have never seen Euphorbia trigona flower. The plant appears to be known from cultivation, like Aloe vera, from what I can tell.

As far as I know, there has never been a modern formal DNA-level taxonomic study into the relationship between Euphorbia trigona and other plants. It is likely a sterile or nearly-always-sterile hybrid of some sort (or an infertile spontaneous mutation) which has existed for hundreds or thousands of years being cultivated and used by indigenous peoples in the central countries of Africa for ritual and religious purposes, as it still is.

By the way, they do flower in India but only rarely. The flowers are very tiny and green, almost not noticeable, and they grow on the ridges of the stems. I suspect they probably flower in their native range, too but not when grown in pots or in most outdoor settings (such as the warm parts of the US which are warm enough but have different weather patterns than central Africa and India). Unless you are staring at it, you wouldn't even see the flowers. I've never seen a seedpod, though (which makes me believe they are sterile).

Jai, think thats lactea. Trigona isnt grown as a native there. And i have seen photos of lactea bloom with teeny tiny flowers, that do actually take effort to look at. I think the lactea being one parent is somewhat probable, but not the dominant one...Only photo that is labeled as such is on world of succulents, but with the plant out of focus.
Baja, i will try...

No, it was Euphorbia trigona. It's cultivated and grows feral, including the red version. The flowers do look somewhat similar to Euphorbia lactea, but they're much smaller from what I remember and more green. In English it is usually just called "milk tree" which is confusing because both Euphorbias are called that.

This is the species I mean: https://sites.google.com/site/...

Most treelike columnar euphorbias are called like that, though some have a afrikaans name...
As for the wild trigona, im not saying its impossible( there is an infestation of a crested cylindropuntia bigelovi from pieces in Africa), but its the first time im hearing off of it. The way i see it , stiffer euphorbias are much less to cause infestation, rather that ones that have a reputation of losing limbs(ingens and tircualii)... or plants that use seeds.....

Well, I've seen it! lol

plant with flowers is a lactea, without a doubt

I tell them apart:
trigona - dense, wide "ribs", leaves, tall, tubercules are exposed, glossy
lactea - broad, less dense, stubby wider ribs, shorter, small leaves, waxy

I asked my contacts in India to see if they can take pictures when theirs are flowering. I'm certain that it's Euphorbia trigonia though. The flowers were really tiny, about 1/4th the size of Euphorbia lactea, and greener than Euphorbia lactea.

I never thought about it explicitly until now, but I'm under the impression that they don't flower in most climates, and when they do the vast majority of people would never notice because they're tiny, green, and very high up on the tree.

Tree? i though it was a tall bush at best..... And im talking old specimens, like
https://commons.wikimedia.org/...
https://commons.wikimedia.org/...

Tall enough that the top was visible/touchable from the balcony. I'll see if they can go back and take pictures of the whole thing.

This picture is similar:

They get taller and wider in India (and presumably central Africa) than they do in the southwest US.

Edit: yes, the second Wikipedia image you edited in is very similar.

WIKi Photos are from lanzarotte.... the place is ideal for euphorbias .... also, canariensis comes from there.....

Yeah, Lanzarotte is idea for some Euphorbias, but not Euphorbias in general. There are thousands of species, and more than half are not even succulents. They're annual, biennial, and perennial herbs.

Well, from what ive seen, ideal for types like lactea, trigona, candelabrum, grandicornis etc. In a nutshell , ideal for most tree and bushy types, like the species in this topic. Im aware that there are a LOT of euphorbia species, as i have observed more than a few here, in the wild and in urban areas too.

The fourth photo on that first link is E. lactea. The most reliable way to tell lactea from trigona is by the orientation of the branches. E. lactea branches go more sideways, less up. All the other stuff tends to be lost in the natural variation of the two plants.

E. trigona can be a proper (smallish) tree with time. The Euphorbia journal is good to see that sort of thing.

With all due respect, I am rather surprised by the certainty and lack of doubt both of you profess (just using your own words, not trying to start trouble) about plants you apparently (I'm only guessing here, and don't let me guess wrong) don't grow yourselves. I usually harbor a great deal of doubt even when I'm pretty sure something is true.

Actually I have grown both Euphorbia lactea (indoors and only for a few years) and Euphorbia trigona. I actually grew up with a 10-foot or so tall stand of Euphorbia trigona. I know pretty well what they look like.

Baja.... i have both trigona and lactea.... ive glared enough at both to see where they differ....

Thank you both, I stand corrected, and in record time. Can you find another picture of E. trigona flowering, Jai? That first one I already commented on is not trigona. But I'm not as certain about that as both of you are, apparently.