Google AI gives the difference between the two, mainly:
Kalanchoe × houghtonii (hybrid mother of millions) and
Kalanchoe delagoensis (mother of millions/chandelier plant) are fast-spreading, succulent succulents that propagate via plantlets,
Kalanchoe × houghtonii is a hybrid of
Kalanchoe delagoensis and
K. daigremontiana (mother of thousands). The primary difference is leaf shape:
Kalanchoe × houghtonii has broader, triangular to boat-shaped leaves, while
Kalanchoe delagoensis has narrow, cylindrical, needle-like leaves.