Cactus identification help.

Hi

Could you help me please to identify this cactus?

It's thin, about 60cm long, with flowers that open only at night.

I live in central Mexico.

I would really appreciate any help. Thank you.

 

Its Nyctocereus serpentinus, now included in Peniocerus by some authors. Its a rather weedy species.

 

Thank you very much!!

I didn't know it was a mexican species. My mother really likes them because of their huge flowers.

Thanks again :)