Epiphyllum laui is a cactus species native to Mexico and grown as an ornamental.

[1] Stems branching basally or laterally; base narrow to subterete for 1–2 cm, flattened portions linear, subobtuse, 5–7 cm wide, midrib prominent, crenate, often slightly undulate; areoles hidden by brownish cream leaves, 2 mm wide and 1 mm long, brownish cream; spines 1-3 (-5), 3–5 mm long, hairlike, brownish yellow; epidermis shiny green, smooth, apices often reddish or brownish.

Even though this plant was discovered in 1975, it was not described until 1990[2] as it failed to flower at the Huntington Botanical Garden.

However, it flowered profusely for Alfred Lau in Mexico, as in several European collections, so Myron Kimnach knew that the plant represented a new species.

In cultivation E. laui seems to prefer high humidity and soil moisture, as well as rather cool conditions.