Schlumbergera (syn. Zygocactus)
This genus encompasses 6 species, including Schlumbergera truncata, called the Thanksgiving cactus because it blooms in autumn. Plants of this species are initially erect, but become increasingly pendent as the segmented branches lengthen. Flowers ranging from pinkish or yellowish white to orangish or purplish red are borne at the end of the stems. The leaf-like segments are 4.5 cm long and 2.5 cm wide, with four prominent tooth-like marginal notches.
In the wild, these brilliantly coloured flowers are pollinated by hummingbirds. Numerous cultivars have been developed from this species, which can be identified by the much more sharply serrated margins of its segments.
The true Christmas cactus is Schlumbergera x buckleyi (syn. S. bridgesii), which normally flowers in December. Over two hundred cultivars of this cross between S. truncata and S. russelliana are available today. The rounded margins of their segments are a distinguishing feature.
The Epiphyllum genus includes 15 species and a number of cultivars that bloom from spring until late summer. Their long flattened stems can grow to 50 cm or more in length and 5 to 12.5 cm in width. The margins of their stems may be smooth, wavy or deeply toothed. Their tube-shaped flowers, often highly scented, are usually white or yellowish, about 8 cm long and 5 to 15 cm wide.
Epiphyllums are commonly called orchid cacti because of their magnificent orchid-shaped flowers.
Hatiora (syn. Rhipsalidopsis)
This genus includes four species, among them Hatiora gaertneri (syn. R. gaertneri) and many different hybrids. It is commonly known as the Easter cactus, because it blooms in spring.
It reaches 15 to 20 cm in height, with a spread of 50 cm. Its flattened segments, which grow to a maximum length of 3.5 cm and a width of about 1 cm, have purplish red margins. Its short tube-shaped flowers, about 3.5 cm in diameter, are red for the species and different colours for the hybrids.