We thought this was a saguaro. Then it bloomed. The flowers look bigger than those of Mexican giant cardon. Picture taken April 28, 2020, 1 PM. Chatsworth, California (inland Los Angeles) TIA

It looks like a happy Saguaro. Their flowers are often huge like this.

It is a Trichocereus (now Echinopsis I guess but it feels very strange to call that particular Trichocereus, Echinopsis) terscheckii aka the Argentine Saguaro.... Gets about the same size, but at about 10x the speed...

I briefly wondered if it was a cross between a saguaro and an echinopsis (if that is possible). We have a small echinopsis at home and it gets big flowers like what I showed.

Kelli said:I briefly wondered if it was a cross between a saguaro and an echinopsis (if that is possible). We have a small echinopsis at home and it gets big flowers like what I showed.

Its an echinopsis, from the terscheckii group. They dont hybridize, as genera they are unrelated. Not even that much within its own genus. More likely a case of convergent evolution than anything else...

On top of that, saguaro's flowers are much shorter, and occupy the upper parts of the trunk, at the crown of the plant, where as the usual rule for echinopsis is on the mid section of the stem.

I will repeat this is E. terscheckii. No question in my mind.

mcvansoest said:I will repeat this is E. terscheckii. No question in my mind.

I agree with you. I looked up pictures and it was an exact match.

I'm sorry for the incorrect ID, Kelli. I took only a fast look and didn't notice the differences. That is quite a plant!

plantmanager said:I'm sorry for the incorrect ID, Kelli. I took only a fast look and didn't notice the differences. That is quite a plant!

No problem