@Baja_Costero @mcvansoest
Looks hybridized...the petals are all wrong....too wide too few

I don't know anything about this cactus, so I would defer to those who do. Here is a Wikipedia article about a relevant taxon

https://en.wikipedia.org/wiki/...

and according to what they say the stigma is always white in the hybrid.

That's a lovely flower, and gigantic indeed.

Surprisingly enough I see plenty of variety in flowers from the same plant depending on time of year, temperature, etc. So I would not discount this as the real thing, just because the flower looks slightly different. Based on the 'in the hybrid the stigma lobes are white, never lavender' statement I'd give this a higher likelihood of being the real thing than most of the other pictures in the entry, most of which have white stigma lobes.... However, I do not (possibly cannot) grow these so I have no expertise to claim.

Could it be an Epiphyllum?
I believe Robert just entered this based on common name and color.

Hi Suzanne, you are spot on as usual! it bloomed after 4 years of having/propagating it (as it grows so fast) I researched and found it is EPIPHYLLUM ACKERMANNII OR RED ORCHID CACTUS, http://www.consultaplantas.com...

Uh yes, because that is a synonym for Disocactus ackermannii, they are the same plant.

That has nothing to do with the contention by Stefan that this is not actually D. (or E.) ackermannii but a hybrid instead. I think he is not correct in that assessment, but it is not a question about if it is Disocactus or Epiphyllum, it is if ackermannii is the correct ID.

Could it be moved to a general genus entry if no one knows for sure?

Yes it can, if everyone agrees, I can put it in the generic Epiphyllum entry since I suspect this may very well be a named cultivar.

The plant should be generic Disocactus if it is anything (see what Thijs said above).

https://www.catalogueoflife.or...

At the moment there is no genus entry for Disocactus.

You're right, Baja. I've created the genus entry and deposited the photo there.

I think it is a mistake to move this plant to a generic entry it is more likely to be D. ackermannii than several of the other images posted under the entry. All those that have white stigma lobes are not D. ackermannii, which is given as a characteristic indicator of plants identified as D. ackermannii actually not being that, but a more prevalent in the trade hybrid.

The plant in this post has the characteristic lavender stigma lobes though on a flower with petals that are slightly larger than one might expect, this is not uncommon for cacti as their flower size, general shape and even color can vary depending on temperature, humidity, etc.

Epiphyllum ackermannii actually is a synonym of Disocactus ackermannii subsp. ackermannii. Should I move it to that entry?

Orchid Cactus (Disocactus ackermannii subsp. ackermannii)

And.... In keeping with Baja's information about the stigma color, should I move the photos with the white stigma in the D. ackermannii entry to the Disocactus x hybridus entry?

Orchid Cactus (Disocactus ackermannii)

And take a look at this entry: Orchid Cactus (Disocactus x hybridus 'Ackermannii')

Is it the same plant and should it actually be named D. x hybridus 'Ackermannii' as Wikipedia suggests? (Wikipedia: "This hybrid is today correctly referred to as Disocactus x hybridus 'Ackermannii'."

Thanks to all for the input! Learning a lot, here is the other pics I'd taken when it bloomed