(Harrisia simpsonii)
Harrisia simpsonii, or Simpson's applecactus, is a species of cactus in the Trichocereeae tribe. It grows in the state of Florida, in the Southeastern United States. Harrisia (applecactus and moonlight cactus) is a genus of night blooming cacti native to Argentina, Paraguay, Brazil, Bolivia, Uruguay, the Greater Antilles, the Bahamas, and the U.S. state of Florida. The genus is named after William Harris, an important botanist of Jamaica. There are about 20 species. Harrisia cactus is an exotic invasive in Queensland, Africa, and the U.S. state of Hawaii. The genera Eriocereus (A.Berger) Riccob. and Roseocereus Backeb. have been brought into synonymy with this genus.