SAGUARO CACTUS. Saguaro is an Indian word. pronunce "sah-wah-ro" The formal name is Carnegiea gigantean. A must have plant for the cactus lovers. The Saguaro cactus is one of the most recognizable of all cacti, as its distinct shape features in many Western movies. its also the larges cactus of the world It is native to the state of Sonora in Mexico and areas of California and Arizona in the USA. This Giant cactus can reach up to 50 ft. tall and it can live about 200 years in its natural environment. Saguaros will do well inside, but also can be placed on a patio in partial sunlight. Do not overexpose the saguaro to sun, but let it adjust slowly. The cactus will burn if placed in full sun for long periods.