This appears to be a Trichocereus x Echinopsis or Echinopsis x Trichocereus hybrid. I bought this plant at a Berkeley Botanical Garden plant sale.

Cuttings of this interesting hybrid cactus plant are sometimes available at Cactus Affinity.

purchased at the Berkeley Botanical Garden Thursday cactus sales

from a Berkeley Botanical Garden plant sale. Unknown collection number.

from a Berkeley Botanical Garden plant sale. Unknown BBG collection number.

from Sacred Succulents. Berkeley Botanical Garden records show the plant in their collection has died.

Berkeley Botanical Garden

from the Berkeley Botanical Garden

Cuttings of Trichocereus peruvianus BBG 48.1540 are sometimes available at Cactus Affinity.

from a Berkeley Botanical Garden plant sale.

From Sacred Succulents, their description "We got this at a Berkeley Botanical Garden plant sale years ago—it looks more like a possible hybrid with one of the “wild” pachanoi rather than the original accession. Fat bluish stems with medium spines.”