Epiphyllum (/ˌɛpᵻˈfɪləm/; "upon the leaf" in Greek) is a genus of 19 species of epiphytic plants in the cactus family (Cactaceae), native to Central America. Common names for these species include climbing cacti, orchid cacti and leaf cacti, though the latter also refers to the genus Pereskia.
The stems are broad and flat, 1–5 cm broad, 3–5 mm thick, usually with lobed edges. The flowers are large, 8–16 cm diameter, white to red, with numerous petals. The fruit is edible, very similar to the pitaya fruit from the closely related genus Hylocereus, though not so large, being only 3–4 cm long. The broad-leaved epiphyllum (Epiphyllum oxypetalum) is particularly well-known. It bears large, strongly fragrant flowers that bloom for a single night only.
Epiphyllum species are added to some versions of the hallucinogenic drink ayahuasca.
The plants known as epiphyllum hybrids, epiphyllums or just epis, which are widely grown for their flowers, are artificial hybrids of species within the tribe Hylocereeae, particularly species of Disocactus, Pseudorhipsalis and Selenicereus. In spite of the common name, Epiphyllum species are less often involved.