Question: what are the giant cactus called in arizona
Answer: The saguaro ( / səˈwɑːroʊ / , Spanish pronunciation : ( saˈɣwaɾo ) ) ( Carnegiea gigantea ) is an arborescent ( tree - like ) cactus species in the monotypic genus Carnegiea , which can grow to be over 40 feet ( 12 m ) tall .