Rooting loose pieces is possible, but not the easiest way to propagate. If you want to propagate the plant, take a small piece from the plant/shoots that is already rooting. It grows pretty quick, so splitting the whole plant is another option. Really want to harvest? Pot this plant in wider pot, so...

Nice lay-out!
It will look great in a couple of years. But if you really want to go for the little tree look (as you are 'supposed to' in traditional bonsai), then there are crassulaceae that are more suitable.

That is not a Crassula.
And yes, it probably is a grass (probably in the Oryzoideae subfamily, if you are interested in grass )

With a cactus on my desk I will probably look at my screen a bit less; I suppose that will do the trick.

Even when dormant I do not keep this species bone dry for too long. I would not leave it like this for months on end. I would say/try; pot and water to at least prevent the roots from d(r)ying off. Given this unusual situation I wouldn't dare giving you more/better advice, sorry. Btw, where did the ...

Beautiful plants, great pictures, thank you.
My wanna-have-list has just gotten a bit longer (no 'thank you' on that front )

If the soil is hiding a caudex, the branching could be just like a densiflorum. Although in that case I would expect the trunk to be thickening at the bottom. Your specimen clearly isn't. Tough one. The spikes are pretty similar to densiflorum as well. What confuses me is the fury coating on the new...

Indeed, not Saundersii, leafs are too flat on this one.

Can't positively ID it though. Is it a single plant? How old? Could it be etiolated?
Maybe (maybe!) Densiflorum...

Watering twice a month seems about right, but it depends on how warm 'quite warm' is. Even more so, it depends on the potting. It could be overwatering; Does the pot have a draining hole (it should), and is this standard potting mix (it shouldn't)? If it is rotting; get it out of that mix asap. It c...

Euphorbia Lactea cristata.
You can find a lot of colour varieties, which are crafted. This one being green is probably a bit stronger, and not grafted?

A mixed pot like this will proof difficult though. Especially the sedum and the cactus are somewhat different in watering needs. And I have my doubts about your soil...

The name of the cultivar is either springtime or bride's bouquet. (i think the latter)

I think it some sort of cross of rupestris

Depending on the species it can take much, much longer. I have a Hoya leaf sitting here for two years now...

(odds are you have a crassulaceae at hand. Then springtime will probably give you new growth)

Thank you. I thought Hummel's Sunset has stripes. But I suppose it as often, or more often, without stripes. And so indeed the one I mentioned. What follows; I suspect the one with stripes is mostly called variegata when it is white, and sometimes it is tricolor when it is more yellowish. Confusing ...

Two more questions from practice: First The regular 'crassula ovata' can be found both all green and yellowish with a red edge. You would expect the latter to be a cultivar, but nowhere can i find a proper name for it. Or is it just a matter of growing regime that defines the amount of green/yellow/...