I believe it is one of the Thai cultivars of Crown of Thorns (Euphorbia milii), possibly 'Millionaire'
The plant next to it looks like a type of Poinsettia, possibly the Jamaican Poinsettia or Euphorbia punicea.
Wow, that is a beauty! And, I'm in agreement with Hetty, it does look a lot like the Thailand cv. 'Millionaire'. Here's a link to one offered by Top Tropical's:
Name: Paul Utah (Zone 5b) Grandchildren are my greatest joy.
On the data base I see an entry for Euphorbia milli with pictures of plants of various colors. Would you who are more knowlegable than I am add it there or add a new entry of 'Millionaire'?
Some may know more than I do about E. milii, but since I moderate the Euphorbia genera in the database, I do believe it looks enough like E. milii 'Millionaire' to create a new entry for that cultivar and put the photos there.
With the hybrids, there seems to always be another possibility but I'm leaving it as E. milii 'Millionaire' for now. I've added that cultivar to the database.
Horntoad said:My original thought was Red Jillian but the flowers of the Red Jillian show leaf-like growth in the center of the flowers and Paul's does not.