Rhipsalidopsis.
Native to Brazil, Plants of the World Online (Kew) recognises the genus and its 2 species Rhipsalidopsis gaertneri and Rhipsalidopsis rosea.
Classification of the two species has been long and complicated with one or both being seen in the genera Epiphyllum, Phyllocactus, Rhipsalis, Schlumbergera, Hatoria and Hariota.
Wikipedia has Family Cactaceae > Subfamily Cactoideae > tribe Rhipsalideae > Genus Rhipsalidopsis.
The Royal Horticultural Society and worldofsucculents.com have “Hatiora formerly known as Rhipsalidopsi”.
They are still seen on some horticultural sites as Schlumbergera.
In situations like this I follow Kew so will use Rhipsalidopsis.
*******************
Hatiora have cylindrical stems and small magenta or orange flowers.
Schlumbergera and Rhipsalidopsis have flat segmented stems.
- Rhipsalidopsis have radially symmetric flowers with free tepals and 1 whorl of stamens.
- Schlumbergera have more bilaterally symmetric flowers with a short floral tube of partly fused tepals and stamens in 2 whorls.
J.F.
