A Stenocereus or Peniocereus? Your photo is too small to allow identification. Is that a short-stemmed clump?

The flowers open at night because the natural pollinators are bats. That also explains their rather large size.

Brad

Hello Redrockrob,
I am no expert so I cannot ID it at all but it is beautifull. I am looking right now for something like this to add to my indoor collection. This cactus makes me miss living in Phoenix. There are so many people I know in NY who have no idea that a cactus can grow and bloom like this. What a beauty!
Andrew

Hello Red Rock...it looks like an Echinopsis of some type. There are a lot of hybrids in this group, so a definite ID is not so easy.

Dave

I'm not expert (at all) but maybe some kind of Echinopsis? It looks just like my Echinopsis multiplex but mine has pink flowers.

see below:

http://www.cactuspedia.info/schede/ECHINOPSIS/photo_gallery_echinopsis.htm

"...native night blooming cactus of the High SW desert"

This rules out Echinopsis. Are you certain it's a SW native, RRR? The flower really does look like Echinopsis.

Brad

That confused me so much that I did not dare to answer first, especially as the picture is so small. Looks like Echinopsis to me too (i.e. South American).

Yep I'm going to go with Echinopsis too, yes many hybrids, and the plant does look like E.multiplex in form, but mine are also only just pink inside, so maybe it does not show in the photo?

Here's the photo enlarged. Not super sharp, but you can see the plants. I'd have to say echinopsis also.
E. oxygona? Can't be sure. But definitely not a USA Native.
Maybe a previous property owner planted it?

{{gwi:472453}}

I guess this could be a non-native, but I was out camping in the high desert NE of Moab, UT and found this growing off a dirt road in the middle of nowhere. I transplanted a part of it into a small indoor cactus pot, but after several years it got too big and I had since moved to AZ. I planted it outside at 4600 ft elevation where it gets down to the teens in winter. It has been doing well, but parts of it died off recently. I have been able to get starts going from it by seperating one or two lobes and sticking them in the ground. I suppose someone could have taken their imported cactus out to the wild, but it seems unlikely!

It's definitely an echinopsis, and there are a variety of ways it might have ended up out in the middle of nowhere. Animals might have moved the seeds around, which happens pretty often. Echinopsis has been in cultivation for a very long time, so there would be plenty of chances for it to escape from cultivation like that.

There might have also been an old homestead out there at one time, and now this is all that remains. Here in the east that happens a lot. Many times I've found places where there's absolutely nothing left of an old house except the plants from the flower garden.

There might be a now unmarked grave where you found it. People have been planting evergreen plants at grave sites for a long time. In my area it's usually yucca,periwinkle, and junipers. But out there, who knows?

Not long ago I was reading on someone's website how they love echinopsis so much that they "stealth garden" with it, by planting it in out of the way places all over the desert. Maybe you found one of their plants, who can say?

It's definitely very cool that you found it where you did and brought some back.