1) Acanthocereus pentagonus 2) Acanthocereus tetragonus 3) Cactus 4) Pitahaya cactus 
• (n.) A cactaceous shrub (Cereus Pitajaya) of tropical America, which yields a delicious fruit.
Pit`a·ha'ya noun [ Spanish , probably from the native name.] (Botany) A cactaceous shrub ( Cereus Pitajaya ) of tropical America, which yields a delicious fruit. 
[n] - highly colored edible fruit of pitahaya cactus having bright red juice
noun highly colored edible fruit of pitahaya cactus having bright red juice; often as large as a peach