Christmas Cactus

The Christmas cactus (Schlumbergera opuntioides) is a species of epiphytic cactus in the family Cactaceae, native to the Atlantic Forest region of southeastern Brazil. It is notably distinct among Schlumbergera species in having more cylindrical stem segments that bear small spine-bearing areoles, giving it a superficial resemblance to opuntia cacti and accounting for its specific epithet. Most other species in the genus have flattened, segmented phylloclades largely lacking true spines. Schlumbergera opuntioides grows in humid montane forests as an epiphyte, anchored to tree branches or rock faces. Its flowers are tubular and zygomorphic, attracting hummingbird pollinators. The species has a more restricted distribution than some better-known relatives and is found at moderate elevations within its Atlantic Forest range. Habitat loss is the principal threat to all Brazilian Schlumbergera species, as the Atlantic Forest biome has been massively reduced through centuries of human activity. Schlumbergera opuntioides is of considerable interest to cactus taxonomists due to its morphological distinctiveness within the genus and has contributed to scientific understanding of evolutionary relationships within Schlumbergera.