Could it be Gymnocalycium calochlorum?

Wow. Perhaps you should read your post again. You absolutely said that it is M herrerae in your opinion.... That means you think it is the same species!

Charlie Glass spent decades exploring the cacti of Mexico, and he determined that M. herrerae and M. albliflora were separate species. That's good enough for me. M. herrerae originates from the Mexican state of Queretero, and M. albiflora is from the state of Guanajuato. What evidence does KarlR hav...

Yes the succulent is a form of Crassula arborescens, something akin to undulatifolia. The Mamms look like they could be M. karwinskiana 'nejapensis'.

Yes, no idea of the correct name, but this THING is as bad as Oxalis, and definitely worse than Bryophyllum sp in the glasshouse, and I would recommend urgent removal and eradication. I have found it to be frost hardy in rural Hampshire for at least the last 10 years! DESTROY !!!!

I am absolutely amazed, that after 14 replies to the original posting of this topic on the forum, no-one has mentioned that for many decades, and currently still to many growers, this plant is known in cultivation not as Disocactus, but as Aporocactus! This is Aporocactus flagellliformis ... also wi...

Yes, I absolutely agree with Tony that this is the white flowered form of Mamm backebergiana. It naturally forms columnar stems, but the plant in the pix does look as if it may have suffered from lack of light at some stages of its life. Many plants with an upright or columnar tendency can be diffic...

Hi JE. I hope that you and yours are doing ok at this weird and difficult time. It's amazing how the inexperienced views of newcomers to the hobby are able to complicate and dominate what used to be simply viewed as basic cultivation aspects of our hobby. Over time I am sure things will relate back ...

Hi Sheila
Great reading as always. Looking forward to a nattter at future cactus gatherings, as and when we are all able to get together.
David

I have raised tens of thousands of cactus and succulent seedlings over the past 40+ years and have never sterilised, microwaved or used boiling water for any of my sowings. I have never used anything more than a fungicide to water my sowings, usually either Chinosol or Fisons Filex when it was avail...