The holiday cacti (Thanksgiving Cactus, Christmas Cactus, Easter Cactus, Crab Cactus, Lobster Cactus) are in the genus Schlumbergera (formerly called Zygocactus). The six species of Schlumbergera are Brazilian epiphytic cacti with irregular, hummingbird pollinated flowers and jointed flat stems that have sharply pointed margins. The genus is named after Frédéric Schlumberger, a French cactus collector from the 19th century.

The Thanksgiving cactus is Schlumbergera truncata and blooms in the fall. The Christmas cactus, often called Schlumbergera bridgesii, is actually a hybrid between Schlumbergera truncata and S. russelliana, first bred about 150 years ago in England. It blooms in the winter when the days are short. Easter cactus is Schlumbergera gaertneri and blooms in the spring when the days are becoming longer. There are now over 200 cultivars of holiday cacti; one even has yellow flowers when grown in cold temperatures that become red when grown in warmer temperatures. They are especially popular in Holland and Denmark, where millions are sold annually.

Holiday cacti can be propagated quite easily by removing a single segment and planting it in slightly sandy soil. They should be kept in a well-lit area (but not direct sunlight) and the soil should be kept moist. The cutting should begin showing signs of growth after two or three weeks.

Because Holiday cacti are epiphytic cacti, they grow best in containers with moist, well-drained soil, although they will need less water when not in bloom. They thrive in bright, indirect light but it is best to void the direct sun of a western window. These plants can be taken outside during the summer months, but place them in the shade or partial shade to avoid sunburn.