The tallest cactus species in the world! These cacti grow 30-60' tall; but don't worry, they grow extraordinarily slowly over hundreds of years. They can grow untouched for decades, so they require very little care from you. Put yours in a hot, sunny location and repot every few years. You should barely have to water it at all.
Potted in a 3g pot; plant is 13" tall.
Bright light to direct sun. Allow long periods of dry soil before watering. (Once ever 4 weeks at the most.) Cacti soil with added perlite or pumice.