The fruits of many cacti are known in tropical America by the name pitaya, also spelled pitahaya, pitajaya, pitajuia, pitalla, and pithaya. These belong to several genera, formerly classified under the genus Cereus, but the best fruits are obtained from the genera Hylocereus and Lemaireocereus. Pitayas are commonly larger than tunas, and by some are considered superior to the latter in quality, but their use is less extensive.
The genus Hylocereus has several species which produce good fruits. The widely cultivated plant which usually passes under the name of Cereus triangularis is properly Hylocereus undatus, Brit. and Rose; the true C. triangularis is found in Jamaica, but rarely elsewhere. All of these plants are climbing in habit, and have three-angled stems. They produce large, showy, night-blooming flowers, and oblong or oval fruits, bright pink to red in color, sometimes more than 3 inches in length, with large leaf-like scales on the surface. The flesh is white and juicy and is filled with numerous minute seeds. In southern Mexico the fruits are used in various ways: they may be eaten out of hand; employed in making cooling drinks and sherbets; and for preserves.
Fig. 61. The pitaya (Hylocereus undatus) is widely cultivated in the American tropics. Its bright rose-colored fruits contain white translucent pulp of pleasant taste ; they are produced by a climbing cactus which bears handsome night-blooming flowers. (X 1/3)
Somewhat distinct are the pitayas furnished by several species of Lemaireocereus, notably L. griseus, Brit. & Rose, and L. queretarensis, Brit. & Rose, and their allies. These are common wild plants in Mexico and elsewhere, and L. griseus is often cultivated. The fruits are globose, about 2 1/2 inches in diameter, and covered with many small clusters of spines. These are brushed off the red fully ripe fruit, leaving it in condition to be eaten. The flesh is dark red to purple, sweet and delicious in flavor.
The propagation and culture of these plants resembles that of the tunas; the Hylocereus group, however, is much better adapted to a moist tropical climate than the latter.