detailed by McMillan and Horobin. The modern genus Schlumbergera was created by Charles Lemaire in 1858. The name commemorates Frédéric Schlumberger, who had a collection of cacti at his chateau near Rouen. Lemaire placed only one species in his new genus – a plant discovered in Brazil in 1837 which had been named Epiphyllum russellianum by William J. Hooker. Lemaire renamed it Schlumbergera epiphylloides (under the current rules of botanical nomenclature it should have been called Schlumbergera russelliana, which is its current name). Lemaire noted the similarity of his Schlumbergera epiphylloides to a species first described as Epiphyllum truncatum by Adrian Hardy Haworth in 1819, but did not accept that the two species should be included in the same genus. In 1890, Karl Moritz Schumann created the new genus Zygocactus, transferring Epiphyllum truncatum to Zygocactus truncatus. Although he later placed it back in Epiphyllum, abandoning Zygocactus, the generic name Zygocactus continued to be widely used. In 1913, Nathaniel Britton and Joseph Rose followed Lemaire in keeping Schlumbergera russelliana and Zygocactus truncatus in separate genera. They also transferred the Easter cactus to Schlumbergera as S. gaertneri, initiating a lasting confusion between these two genera. In 1953, Reid Venable Moran placed both Schlumbergera russelliana and Zygocactus truncatus in the genus Schlumbergera. Other species were added later by David Hunt, including those formerly placed in Epiphyllanthus. Schlumbergera and Hatiora have long been confused. Species in the former genus generally have flowers that are zygomorphic with a distinct floral tube, while those in the latter have actinomorphic flowers with inconspicuous tubes. DNA data showed that as previously circumscribed the two genera are not monophyletic and the three species in Hatiora subgenus Rhipsalidopsis were transferred into Schlumbergera, although this change has not been universally adopted, with other sources placing two in the genus Rhipsalidopsis. Synonymy The following genera are now synonyms of Schlumbergera (i.e. they have no species not moved into Schlumbergera): Epiphyllanthus A.Berger Opuntiopsis Knebel (nom. inval.) Zygocactus K.Schum. Zygocereus Frič & Kreuz. (orth. var.) Epiphyllum Pfeiff. but not Epiphyllum Haw. The case of Epiphyllum is complex. In 1753, Carl Linnaeus created the genus Cactus. As more species were discovered this proved too broad, and new genera were set up to subdivide the cacti. The genus Epiphyllum was created in 1812 by Haworth, based on Linnaeus's Cactus phyllanthus. In 1831, Johann Link created the genus Phyllocactus based on the same species. Following Ludwig Pfeiffer