Hylocereus ocamponis -
Pitahaya roja. The skin as well as the sweet pulp of the fruit are wine-red color. Usually eaten out of hand. Also grown as an ornamental hedge plant. [Cornucopia II, page 64. Stephan Facciola, Kampong Publications 1998].
Note: the cacti seen behind and under the bud in the photo are not H. ocamponis.