Selenicereus hamatus is a species of Cactaceae and produces one of the largest flowers in the family.

A. Berger seems to belong here, but it is impossible to know for sure as the original description is brief and no type seems to exist.

Stems scandent, clambering or sprawling, branching, producing few aerial roots, very vigorous, to 5–12 m long or more, often growing 2 m or more in a season, 16–22 mm thick; ribs 4 or rarely 3-5, strong, later terete, acute; areoles small, brownish or black, remote, on the upper edges of knubby projections, these often forming obtuse, deflexed spurs about 1 cm long, internodes 4–5 cm; spines 5-6, ca 5 mm long, whitish, bristle like, 1-3 lower or central spines usually brown or black; epidermis glossy grass or light green.

Flowers produced one by one over a longer period than most other species, born sparingly near tips of mature stems, 30–40 cm long, 20–30 cm in Ø,[1] nocturnal and strongly scented with an aromatic fragrance, tepals rotate, inner ones forming a broad cup; pericarpel oval, knobby, ca 4 cm thick, covered with white spines and brown or black hairs, bracteoles green with white tips.

; receptacle ca 10–14 cm long, green, purplish towards the apex, ca 22 mm in Ø, its areoles with short, retuse, 1–12 mm long bracteoles, long black hairs and spines, upper bracteoles longer, the uppermost tipped purple; outer tepals 15 cm long, in 4 series, the outermost more narrow, reddish purple outside, chrome yellow inside, innermost broader, to 2 cm, acute to acuminate, greenish yellow outside, chrome yellow inside; inner tepals 12 cm, in 3 series, very broad, retuse, mucronate, white; stamens creamy white, anthers yellow; style thick, longer than the stamens, yellowish, lobes 15-18.