This debate has been going on now in my circle of succulent 'experts' for some time now. What is the REAL Euphorbia ingens? If you google it, you will find that there are a LOT of very different candellabra type Euphorbias identified as this species.

MY understanding was/is that this is the gigantic Euphorbia from South Africa characterized by relatively 'smooth', 4-sided (usually) columns, small to insignificant spines, rarely leaves (though they do exist in spring, but are almost invisible), and flowers like mad in the fall only near the tops of the columns.

However, some of colleagues think this is a description of Euphorbia abyssinica. MY understanding is that that is a 'neater', also 4-sided candellabra type Euphorbia with pronounce paired spines, sharper-edged columns, and prominent leaves in summer. Also, flowering tends to be up and down much of the length of the tallest columns, unlike the case with ingens where it's primarily at the top. I personally, however, don't know how to tell this species from the non-variegated forms of Euphorbia ammak. Maybe someone who really knows can fill me in on that one, too while they're at it.

Can anyone assist me, or tell me where to go and find the answer (I need a really reliable source- too many internet 'euphorbia' experts disagree with each other).