Origin of moon cactus

Question

If moon cactus has no chlorophyll and can’t survive on its own without being grafted to a host cactus, then how did it survive in the wild and grow old enough to reproduce?

Answer 1

Since there are over 80 known species of Moon Cactus, there's a good chance they all came from a far fewer number of specimens that, over time, naturally grafted to other chlorophyll-producing plants, and among themselves, in the wild.

If you have a Moon Cactus or are considering getting one, this article contains information on their care:

https://www.gardeningknowhow.com/ornamental/cacti-succulents/moon-cactus/care-of-moon-cactus.htm