This plant is not E. didieroides, based on the cyathia in the second picture.



The cyathia of E. didieroides appear on a long(ish) peduncle and the cyathophylls are characteristically erect (mostly closed tight around the glands).

The plant pictured is another one of the Madagascar Euphorbias, but I could not say which one at this point.

I will propose these 2 images be moved to the genus entry for Euphorbia unless anyone has input which may help with the identification.

I realize this is an image from Wikipedia Commons, but they got the name wrong. Interestingly (only) one of the images on that Wikipedia Commons page (the first) looks like it is actually correctly identified.

https://commons.wikimedia.org/...