Harrisia martinii, commonly called the Martin applecactus, is a species of night-blooming, rope-like cacti native to South America.

[2] With large showy flowers that attract the hawk moth, it is considered by some a useful landscape plant in areas that do not freeze.

[3] Harrisia martinii grows richly branched with spreading, green to gray-green shoots that reach lengths of up to 2 meters or more with diameters of 2 to 2.5 centimeters.

[5] The species was first found in Brazil in 2007 Harrisia martinii is considered an exotic invasive in Australia,[2][6][7] South Africa,[8] and the U.S. state of Hawaii.

The specific epithet martinii honors the French cactus lover Raymond Martin from Toulouse.