This is a young cutting of the Trichocereus bridgesii, a beautiful blue, grey member of the San Pedro family. It is not large enough for consumption yet, but you can put it in the earth to grow.
Trichocereus bridgesii is a fast-growing columnar cactus from the high deserts of Bolivia. It can grow 2–5 m tall with stems of up to 15–20 cm in diameter. Among the indigenous populations of Bolivia, both cacti T. bridgesii and T. pachanoi are also known as Achuma or Wachuma.