Acanthocereus is a genus of cacti. Its species take the form of shrubs with arching or climbing stems up to several meters in height. The generic name is derived from the Greek word άκανθα (acantha), meaning spine, and the Latin word cereus, meaning candle. The genus is native to the mostly tropical Americas from Texas and the southern tip of Florida to the northern part of South America, including islands of the Caribbean.

The Cactoideae are the largest subfamily of the cactus family, Cactaceae, and are widely distributed throughout the Americas. Cactaceae is the 5th most endangered plant or animal family evaluated globally by the International Union for Conservation of Nature. Around 80% of cactus species belong to this subfamily. The genera of the Cactoideae are characterized by microscopic foliage leaves. All photosynthesis occurs in shoot cortex cells covered by a persistent epidermis and stomata. Another important characteristic of this subfamily is ribbed stems, which enable the inner cortex to expand radially without breaking the shoot surface to absorb large quantities of water.