Taxon	Illustrator ⠉
	Hylocereus undatus Selenicereus grandiflorus Epiphyllum phyllanthus var. hookeri	John Myers John Myers John Myers

Shrubs, epiphytic, hemiepiphytic, or epipetric, straggling, climbing, scandent, or pendent, irregularly many branched. Roots diffuse, often adventitious along stem internodes. Stems segmented, green, blue-green, gray-green, or somewhat whitish with wax; segments elongate, 3-winged or angled, length highly variable, 10–500+ × [1–] 4–7.5 [–10] cm, distinctly narrowed proximally, glabrous; ribs (2–) 3 (–5), winglike to narrowly triangular in cross-section, rib crests straight to undulate, crenate [toothed, notched, or lobed], often with a line of hard, brown to gray bark between areoles; areoles (10–) 35–50 mm apart along ribs, oval, short woolly, sometimes subtended by minute, vestigial leaves at growing stem tip; areolar glands inconspicuous; cortex and pith mucilaginous. Spines 0–4 [–8] per areole, whitish or yellowish to brownish [blackish or red, aging gray], acicular [awl-shaped or hairlike], straight, terete, generally short, 0–4 [–10] mm, hard, bases sometimes conic or swollen, smooth, glabrous; radial and central spines not distinguishable. Flowers nocturnal, lateral to subterminal on 1+-year-old stems, at adaxial edges of areoles, long tubed, funnelform, [3–] 25–29 [–38] × [8–] 15–25 [–30] cm; outermost tepals often greenish, yellow, pink, or occasionally purplish red or white, 10–15 × 1–1.5 cm, margins entire; inner tepals white to cream [rarely pinkish or red], 10–15 × 1.5–2.5 cm, margins entire; ovary tuberculate [to smooth], scaly, spineless, usually without hairs or wool; scales triangular, broad, thick conspicuous, to 25 mm; stigma lobes to 24, white. Fruits irregularly dehiscent along 1 side, red [to purple or magenta], oblong to ovoid or spheric, [20–] 50–125 × 40–120 mm, fleshy, spineless; pulp white; scales persistent, green, triangular, conspicuous, thick and fleshy, to 4+ cm; floral remnant often persistent. Seeds black, [elongate or] pyriform [to reniform], 2–3 mm, glossy; testa smooth or minutely textured. x = 11.

Distribution

Introduced; subtropical and tropical regions of Mexico, West Indies, Central America, n South America

Discussion

Species 18 (1 in the flora).

Selected References

None.

Lower Taxa

Hylocereus undatus

"thick" is not a number. "thick" is not a number. "broad" is not a number.