Hylocereus undatus (Haw.) Britton & Rose in Britton, Fl. Berm. 256. 1918.
Basionym: Cereus undatus Haw.
Much branched vine, creeping or climbing by aerial roots, attaining 7 m in length. Stems fleshy, 2-5 cm wide, trigonal, with 3 longitudinal ribs with undulate margins, with depressions in which are found groups of 1-5 subconical brown spines, 3-4 mm long. Flowers solitary, up to 30 cm long, axillary to the group of spines or terminal on the branch; perianth glabrous, infundibuliform; outer tepals greenish yellow, sometimes with a reddish tinge, those of the hypanthium ovate-lanceolate, the distal ones linear-lanceolate, the inner tepals petaliferous, white, longer than the outer ones; stamens yellow; inserted; stigmas greenish yellow. Berry red, ellipsoid, fleshy, 6-12 × 5-7 cm, with persistent tepals; seeds numerous, minute, black, covered with a red pulp.
Phenology: Flowering from July to September and fruiting from September to December.
Status: Exotic, uncommon, cultivated and naturalized.
Selected Specimens Examined: Acevedo-Rdgz., P. 11494.
Distribution: Cultivated from the coast to the Cordillera Central, naturalized in dry or coastal areas. Native to Mexico, but widely cultivated in the tropics. Also on St. John and St. Thomas.
Public forest: Guánica.