Peruvian Apple Cactus, Cereus repandus, is a large, erect, thorny columnar cactus found in South America as well as the nearby ABC Islands of the Dutch Caribbean. It is also known as Giant Club Cactus, Hedge Cactus, cadushi, (in Wayuunaiki) and kayush.
With an often tree-like appearance, the Peruvian Apple Cactus' cylindrical gray-green to blue stems can reach 10 metres (33 ft) in height and 10–20 cm in diameter. The nocturnal flowers remain open for only one night. The fruits, known locally as "pitaya" or Peruvian Apple, are thornless and vary in skin colour from violet-red to yellow. The edible flesh is white and contains small, edible, crunchy seeds. The flesh sweetens as the fruit opens out fully.
Cereus repandus is an unresearched, under-utilized cactus, grown mostly as an ornamental plant. As noted above, it has some local culinary importance. The Wayuu from the La Guajira Peninsula of Colombia and Venezuela also use the inner cane-like wood of the plant in wattle and daub construction.
Thanks to wikipedia.org