That particular Rhipsalis makes small whitish berries with no flavor. The fruit in the pot in the pic are from the Melo. (There's one still hanging on the top.) The hairs on the cephalium are so tight that as the fruit grows, it is forced up and out. The fruit are hollow and tasteless, and few seeds are inside. Rhipsalis species. The large stems are one species, the gold flowers belong Hatiora (Rhipsalis) salicornioides, and the white flowers and small green stems are the third species that co-habit with the Melocactus. I've had houseplants since I was a kid. Some followed me around the country for 10 years, but the majority became succulents in the mid 90s. With the internet came the opportunity to find formerly obscure things like cactus seeds and people who were growing more than they could want. The 2 things go hand in hand. I still have many plants that are 20 years old, including an Espostoa guentheri that is now about 9ft. tall and reaching the roof of the greenhouse. Anybody want to come get it?

That is a great example of microclimates JoJo! The time spent at the minimum temperature (minutes, hours, days) plays a big role in what temperatures a plant can survive. So does the amount of water in the plant, and in the soil. Dry plants are much more tolerant of cold compared to wet plants. Plants in the ground can survive colder temperatures than plants in pots. I have found most of my plants can tolerate much lower temperatures than typically listed. These lows are brief, just a few hours at most, and it's at least 20 degrees warmer during the day. So plants that are supposed to not go below the mid-thirties F can tolerate minimum temperatures in the high twenties. Agave ferdinand-regis is listed at both +5, and -12 in the list above. The difference between a minimum average temperature, absolute minimum temperature, and Fahrenheit and Celsius scales is often confused. Minimum temperature listings should be regarded with great suspicion, even when coming from a more or less credible source like Desert-Tropicals. It is better to research the plants natural environmental conditions. I would not give much credence to this, or any other so called 'minimum temperature' list. There are too many variables for these to be accurate to any degree. ;) Brad

Reminds me of echinocactus grusonii that's been grown in too much shade

Could be Mammillaria magnimamma or karwinskiana. It's quite like a couple I've got labelled karwinskiana.