First flower... unknown Echinopsis

Had this plant four years and this is its first flower. It's crazy big! For reference the pot has a diametre of 25cm.

Flower size relative to the plant size is ridiculous.

That's a beauty... I think Echinopsis flowers might just be my favourites among all the Cactaceae. As to the ID... I'd say it's probably a hybrid with a bit of eyriesii in the mix. The flower looks like it might have traits from one of the old Trichocereus members as it seems very "full" compared to those usually seen on the usual globular Echinopsis species. The spines and ribs also resemble a clumping variety that I've got growing. It's yet to flower, and until it recently started it's multi-headed growth habit I was considering it to be a spachiana.

This one 'outdoors' beautifully down here in Tas... doesn't mind a wet winter. However, this year I actually kept it in the greenhouse and dry for the whole of winter and this it decided to flower for me. Temperature got to -4 in the greenhouse but no frosts. There are two more buds on it at the moment too but it looks like it has decided to channel its energy into this one big flower as the other two buds are actually shrinking away.

As for an ID... I posted this plant a few months back and Geoff mentioned it looked like E. Schickendantzii (see here: http://forum.auscactiforum.net/american-mexican-cacti-f14/e-cinerascens-t851.htm#9231). It still has that look about it too I think.

Yeah, I can definitely see that in the flowers. The growth habit has me puzzled, but I suspect environmental factors could be the cause.

All up, it's a spectacular plant.

love it,want it lol...could it be Echinopsis werdermannius ?

heres my E. Schickendantzii , yours is so much more globular