Cleistocactus azerensis
The hummingbirds love these cacti. Our specimen plants have literally billions of blooms on them right now, and all summer long. I counted. First they bloom on the south side of the plant, all up and down. Then the blooms migrate around to the west and east sides, with a few on the north side popping by late summer.

The hummingbirds are territorial, so we see the same pair every day, checking for new buds here when they’re not finishing off the last of the Aloe striatas, which are just dripping with nectar.