Selenicereus undatus, the white-fleshed pitahaya, is a species of the genus Selenicereus (formerly Hylocereus) in the family Cactaceae and is the most cultivated species in the genus. It is used both as an ornamental vine and as a fruit crop, the pitahaya or dragon fruit.นิดดา หงส์วิวัฒน์ และทวีทอง หงส์วิวัฒน์. แก้วมังกร ใน ผลไม้ 111 ชนิด: คุณค่าอาหารและการกิน. กทม. แสงแดด. 2550 หน้า 37 - 39
Like all true cacti, the genus originates in the Americas. S. undatus is native from Mexico to Honduras; it may be a hybrid.
Description
Plant The stems are scandent (climbing habit), creeping, sprawling or clambering, and branch profusely. There can be four to seven stems, between or longer, with joints from or longer, and thick; with generally three ribs; margins are corneous (horn-like) with age, and undulate.
Areoles, that is, the small area bearing spines or hairs on a cactus, are across with internodes . Spines on the adult branches are long, being acicular (needle-like) to almost conical, and greyish brown to black in colour and spreading, with a deep green epidermis.
Flowers The scented, nocturnal flowers are long, wide with the pericarpel long, about thick, bracteoles ovate, acute, to 2.5 to less than long; receptacle about thick, bracteoles are linear-lanceolate, long; outer tepals lanceolate-linear to linear, acuminate (tapering to a point), being long, wide and mucronate (ending in a short sharp point). Their colour is greenish-yellow or whitish, rarely rose-tinged; these outer tepals, or sepals, are about 65 in number, and bring the flower to a total width of up to .Reisigl, World of Flowers, loc.cit. The inner tepals are lanceolate (tapering to a point at the tip) to oblanceolate (i.e. more pointed at the base), up to long about wide at widest point, and mucronate, unbroken, sharp to acuminate (pointed), and white.
Stamens long, are declinate, inserted in one continuous zone from throat to above the pericarpel and cream. The style (bearing the stigma) to 17, they are long, stout, thick, cream, and up to 26 stigma lobes, they can be whole or sometimes split at the top, cream, about long. Nectar chambers are long.
Fruit
The fruit is oblong to oval, long, thick, red with large bracteoles, with white, or more uncommonly, pink pulp and edible black seeds.
Habitat Selenicereus undatus is lithophytic or hemiepiphytic. It is widely distributed through the tropics in cultivation. It is a sprawling or vining, terrestrial or epiphytic cactus. They climb by use of aerial roots and can reach a height of or more growing on rocks and trees.
Systematics This species is closely related to S. ocamponis and S. escuintlensis. Selenicereus undatus was described by (Haw.) Britton & Rose and published in Flora of Bermuda 256. 1918. In 2017, D. R. Hunt groups the genus Hylocereus within the genus Selenicereus. This has been supported by a phylogenetic analysis of the tribe Hylocereeae (Korotkova, et al., 2017), therefore this species is now treated under the name Selenicereus undatus
Taxonomy The species epithet undatus in Latin means "wavy" from unda "wave", referring to the wavy edges of its branch ribs.
Common names Other common names in English include night blooming cereus, strawberry pear, belle of the night, Cinderella plant, Jesus in the cradle and moonflower.
See also Pitahaya List of culinary fruits
References
External links
Dragon fruit plant grower's tips, greenhouse, flower and more