Dragon Fruit

Hylocereus undatus is sporadically naturalized in tropical and subtropical regions worldwide where it is cultivated for its large, edible fruits and beautiful flowers, which are among the largest in the cactus family. In Florida, H. undatus has escaped from cultivation in nine counties, forming large colonies in some areas. Individuals of this species grow prolifically and may soon overrun their substrate. Whether populations of H. undatus in the United States are merely persisting or are also reproducing sexually remains unclear.

The vernacular name night-blooming cereus has been applied to several genera of cacti with large, nocturnal flowers.

This species was first introduced to China in 1645. It is usually cultivated as a hedge, or for its edible fruit. The flower is often eaten in a vegetable soup in S Guangdong.

Plants sprawling or clambering over rocks, shrubs, and trees. Stems usually sharply 3-angled, to 500+ × 4-7.5 cm; ribs with undulate margins and gray, hornlike bark; areoles 2 mm diam. Spines 1-4 per areole, brownish gray, inconspicuous. Flowers fragrant; outer tepals white, outermost strongly reflexed, midstripes yellowish green; inner tepals white, broad, oblanceolate; filaments 50-75 mm; style cream, 175-200 mm. Fruits spheric to oblong. Seeds 2 × 1 mm. 2n = 22.

Plants clambering or sprawling. Stems deep green, 3-15 m. Joints 20-50 × 3-8(-12) cm, winged or angled, margins of wings or angles coarsely crenate, horny. Areoles 3-6 cm apart, 2-5 mm in diam. Spines 1-3(-6) per areole, spreading in various directions, gray-brown, conic to subulate, 2-5(-10) mm. Flowers 25-30 × 15-34 cm. Receptacle tube funnelform. Sepaloids with greenish midrib and mostly white margin, lanceolate-linear to linear, 10-15 × 1-1.5 cm, margin entire, apex acuminate, reflexed. Petaloids erect to spreading, white, narrowly oblanceolate, margin entire or erose. Filaments cream, 5-7.5 cm; anthers linear, ca. 4.5 mm. Style cream, 14-20 cm, stout; stigmas 20-24, exserted, 2-2.3 mm, slender. Fruit red, globose to ellipsoid, 7-12.5 × 6-12 cm, with numerous triangular scales, umbilicus small; pulp white. Seeds obovate, ca. 2 × 1 mm. Fl. July-Dec.

introduced; Fla.; Mexico; West Indies; Central America; n South America.

S Fujian, S Guangdong, SW Guangxi, Hainan, Taiwan [perhaps native to Mexico and Central America; widely introduced and escaped in tropical Asia, E Australia, and South America].

Flowering year-round.

Disturbed sites in sandy soils [tropical deciduous and semideciduous forests]; 0-50m.

Trees, rocks, maritime scrub; sea level to 300 m.

Cereus undatus Haworth, Philos. Mag. Ann. Chem. 7: 110. 1830

Cereus undatus Haworth, Philos. Mag. Ann. Chem. 7: 110. 1830.