Mendozan Cactus
This Argentine cactus seems to be the only member of the genus. Related to the Oreocereuses and Matucanas, you can really see that bright red tubular flower would attract hummingbirds for miles around.
Denmoza rhodacantha
Until this bloomed we had no idea what it was. We figured it was probably a Ferocactus, but then it bloomed and the answer was not so much.