Stenocereus fruit (sour pitayas) are a variety that is commonly eaten in the arid regions of the Americas. They are more sour and refreshing, with juicier flesh and a stronger taste. The sour pitaya or pitaya agria (S. gummosus) in the Sonoran Desert has been an important food source for Native Americans. The Seri people of northwestern Mexico still harvest the fruit, and call the plant ziix is ccapxl – "thing whose fruit is sour". The fruit of related species, such as S. queretaroensis and thedagger cactus (S. griseus), are also locally important food. The Organ Pipe Cactus (S. thurberi) fruit (called ool by the Seris) is the pitaya dulce ("sweet pitaya"). It still has a more tart aroma than Hylocereus fruit, described as somewhat reminiscent of watermelon; it has some uses in folk medicine.
Fruits of some other columnar cacti (mainly Cereeae) are also called "pitayas" – for example those of the Peruvian Apple Cactus (Cereus repandus), which are very rare.(quote from wikipedia)
